One Piece Power Level Discussion Thread

[goldb]

Ground Rules for the Power Level Discussion Thread
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As always, please follow the guidelines set by the Forum Rules that apply across the board.

It's important that discussions from a current chapter are spoiler tagged until 24h have passed from an english release.

• For the sake of constructive discussion, where and when possible please quote/ source any information you provide. Particularly when it comes to conversations carried over from other threads.
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• We will strive to avoid repetitive discussions and any extensive battle topics will be guided to the Davy Back fight to existing threads or new ones can be made there.

As of now these topics are shelved due to repetitiveness or until the manga can present us with material to further discussions:

1. Shanks v Mihawk
2. Hand to hand fighters > Swordsmen
3. Zoro > Luffy
4. Zoro v Sanji
5. Is Smoker a top 30 character?
6. Mihawk's rank within the story
7. Law having CoC currently.
8. Katakuri > Kaido/Luffy/Etc.

If you wish to continue any of these discussion and remove it from the list, you will need to provide manga material as proof. If there's also anything you think we've covered numerous times, let me know and I'll update the list.

This is the only warning there'll be regarding these ground rules, anything no adhering will be removed. So please just check your posts before posting them.

 

[Pandora]

As if an admiral can take on a Yonko in a 1vs1
I cannot picture this happen at all... Tho I can see Akainu pull it somehow

I agree if it were three admirals vs one Yonko then that would a fight but an admiral vs a Yonko would be a one sided slaughter .

 

[Eigengrau]

The World Government is assuming Big Mom and Kaidou are joining forces, but the fact also is, they are aware that Kaido is already aligned his forces with the Shogun. And the Shogun are still a mystery to even the World Government, which is why, they are treading carefully in engaging either one of the Yonkou and their pirate crews.

Plus, Borsalino could more than likely take on two Yonkou by himself, given what he did with the Supernovas way back, during the slave auction, where Rayleigh was first introduced. The Admirals are powerful.

I gotchu fam, don't listen to the naysayers.
I've always considered Kizaru to be the strongest pre-timeskip Admiral as well.

While I don't think he could take on two Yonkou at the same time, I'm certain he'd do a much better job than everyone else.

 

[Zehahaha]

I agree if it were three admirals vs one Yonko then that would a fight but an admiral vs a Yonko would be a one sided slaughter .

Don't think it would be a one sided slaughter either, Admirals are not weak punks but I would still see a Yonko winning anytime anyday
Although Akainu can do it imo, if even BB felt the need to gtfo once he saw Akainu there, despite days before taunting the entirety of Marineford, then it does show that Akainu is no pushover (and I expect same from Aokiji and Kizaru). But can't help but think that the Yonko are a notch above, especially Shanks

 

[Pandora]

Don't think it would be a one sided slaughter either, Admirals are not weak punks but I would still see a Yonko winning anytime anyday
Although Akainu can do it imo, if even BB felt the need to gtfo once he saw Akainu there, despite days before taunting the entirety of Marineford, then it does show that Akainu is no pushover (and I expect same from Aokiji and Kizaru). But can't help but think that the Yonko are a notch above, especially Shanks

You are right ^^ if it's three admirals vs a Yonko I could see the admirals winning .If it's an admiral vs a Yonko no way would the admiral win but he would put up a fight . If it's Akainu vs a yonko perhaps it would end up as a draw .

 

[Pirate Queen]

The World Government is assuming Big Mom and Kaidou are joining forces, but the fact also is, they are aware that Kaido is already aligned his forces with the Shogun. And the Shogun are still a mystery to even the World Government, which is why, they are treading carefully in engaging either one of the Yonkou and their pirate crews.

Plus, Borsalino could more than likely take on two Yonkou by himself, given what he did with the Supernovas way back, during the slave auction, where Rayleigh was first introduced. The Admirals are powerful.

*plus, Akainu survived a duel with Whitebeard by himself and now he's running the Marines. And we don't know the true power of the 5 Elder Stars.

Bruhhhhhhhh WHOSE MAN IS THIS??? SOMEBODY COME GET THEY MAN!!!!!

 

[Hannibal Psyche]

An Admiral take on 2 Emperors alone? That's absurd.

 

[M3J]

Can anyone prove that an Emperor would beat an admiral? Or vice versa? I mean, although Whitebeard was owning Akainu, Akainu still got back up and kept on fighting.

 

[Eigengrau]

Can anyone prove that an Emperor would beat an admiral? Or vice versa? I mean, although Whitebeard was owning Akainu, Akainu still got back up and kept on fighting.

Well, we haven't seen anything from Kaido/Shanks at this point, so I don't think it would be fair to bring them up as examples.

But as for Big Mom... I don't know, like, if I imagine Kizaru going one-on-one against her, I just don't see how he could possibly lose.

I'm not shitting on Big Mom or anything, we saw how scary and powerful she can be (even though I don't think we've seen the full extent of her powers yet, as in, giving it 100%), but I mean... how exactly would she do anything to Kizaru?

I just don't see her being able to match and/or evade his speed and attacks.

I don't know, seems like he could get the job done in my opinion, but this is all subjective, there's no way for me to actually give any kind of proof.

But I mean, she's only 4 years younger (68) than Whitebeard at the time of his death. She can be a Yonko all she wants, but there's no way she's still in her prime, which should be taken into account as well, whereas Kaido/Shanks/Blackbeard still look relatively young.

I can see Kaido needing 2 Admirals at least to take him down, but guys like Shanks and BB would probably have their hands full with just one of them... but we'd have to see more of everyone from both sides before actually making up our minds.

In the end I think the DFs end up playing a big part as well for sure, but when it comes to Big Mom I just don't see her being able to top the Admirals who should all currently be in their prime.

~

But that's all a bit off-topic, so to try and get things back on track and speaking of Yonko...

What if this "Rocks" talk was brought up to foreshadow Kaido and Big Mom actually teaming up?

Do you guys think that would be cool, or would you prefer to have each Yonko do their own thing and remain an individual faction?

At this rate they might really end up together and after finding One Piece they'd be dubbed King and Pirate Queen ...

Also as it was pointed out, if Kaido and Big Mom allied forces, they would also have Wano to back them up, and then what?

All Yonkou (except BB) would gang together/side with Luffy against the WG or something? Can't say I like that idea but I'm just spitballing here.

I can't say I'm looking forward to seeing Yonko team up. With the Supernovae it's one thing I guess, everyone is trying to make a name for themselves for better or worse, but with the Yonko it's different since they're all notorious figures who already control the New World, so it seems a bit unnecessary...

But if Kaido and Big Mom were really part of the same crew at some point, then that's definitely interesting and something to look forward to.

Maybe that's why they "promoted" Luffy to Yonko as well? That way we'd have 2 working together + 3 on their own.

Either way, with the Shichibukai system soon to (probably) be abolished, I wonder if the same thing won't happen to the Yonkou as well.

After Wano and if a Yonko is utterly beaten, well... will they still be considered a Yonko? Will they still hang around knowing that others will probably get to One Piece before them? Is there any interest at all in keeping them around after they've been beaten?

So how likely is it that they get killed for real? Maybe BB sneaks in at the last minute and delivers the finishing blow to one of them or something, maybe.

Because Kaido/Big Mom getting beaten and then trying to make Luffy reach Raftel/become Pirate King seems like a big, big stretch. Not sure I'd want to see that happen.

I mean with Big Mom it would kinda be okay since she's pretty much a grandma and be all like "yeah sure whatever, go get 'em, I'm too old for this crap anyway" or something.

Just some rambling thoughts, sorry

 

[McNuss]

Can anyone prove that an Emperor would beat an admiral? Or vice versa? I mean, although Whitebeard was owning Akainu, Akainu still got back up and kept on fighting.

I wouldn't even say he was owning Akainu. I mean, it was very a very emotional scene, you could see how sad and angry Whitebeard was. But objectively, I would even go so far and say that Akainu won that clash. Sure, Whitebeard knocked him out for a few minutes, but the prize was that he lost half his face, an injury that would have killed him if it weren't for Blackbeard's killsteal. And Akainu took that prize in an instant. Halffaced Whitebeard didn't have enough strenght left in him to finish Blackbeard, while Akainu steamrolled Ivankov and Inazuma, faced all of the remaining Whitebeard Commanders, plus Crocodile and Andre, and defeated Curiel and just ignored the rest while continuing after Luffy.

Oda said if Akainu where the protagonist, he would find One Piece in two years. Due to that, I believe he is stronger than the Yonkou or would quickly become stronger than them if he chose to challenge them.

Akainu blowing up Whitebeards face was also so symbolic because he destroyed his white beard. Whitebeard was Akainu's victory.

 

[Hannibal Psyche]

Can anyone prove that an Emperor would beat an admiral? Or vice versa? I mean, although Whitebeard was owning Akainu, Akainu still got back up and kept on fighting.

Whitebeard cannot be used as he was in a league of his own. Admirals and Emperors equally got handed by him when they fought him.

Only Admirals have gone after Emperors and Emperors need be able to fight with Admirals to advance. The Manga pretty much implies outside of Roger and Whitebeard, they're relatively as strong as the other. Roger and Whitebeard were just leagues ahead of everyone else.

 

[thedude]

But as for Big Mom... I don't know, like, if I imagine Kizaru going one-on-one against her, I just don't see how he could possibly lose.

I'm not shitting on Big Mom or anything, we saw how scary and powerful she can be (even though I don't think we've seen the full extent of her powers yet, as in, giving it 100%), but I mean... how exactly would she do anything to Kizaru?

I just don't see her being able to match and/or evade his speed and attacks.

I don't know, seems like he could get the job done in my opinion, but this is all subjective, there's no way for me to actually give any kind of proof.

We saw Raleigh hold his own against Kizaru and it wasn't speed based. It was with Haki. Not sure why Big Mom would be any different.

 

[M3J]

Well, we haven't seen anything from Kaido/Shanks at this point, so I don't think it would be fair to bring them up as examples.

But as for Big Mom... I don't know, like, if I imagine Kizaru going one-on-one against her, I just don't see how he could possibly lose.

I'm not shitting on Big Mom or anything, we saw how scary and powerful she can be (even though I don't think we've seen the full extent of her powers yet, as in, giving it 100%), but I mean... how exactly would she do anything to Kizaru?

I just don't see her being able to match and/or evade his speed and attacks.

I don't know, seems like he could get the job done in my opinion, but this is all subjective, there's no way for me to actually give any kind of proof.

But I mean, she's only 4 years younger (68) than Whitebeard at the time of his death. She can be a Yonko all she wants, but there's no way she's still in her prime, which should be taken into account as well, whereas Kaido/Shanks/Blackbeard still look relatively young.

I can see Kaido needing 2 Admirals at least to take him down, but guys like Shanks and BB would probably have their hands full with just one of them... but we'd have to see more of everyone from both sides before actually making up our minds.

In the end I think the DFs end up playing a big part as well for sure, but when it comes to Big Mom I just don't see her being able to top the Admirals who should all currently be in their prime.

But how is Kizaru going to hurt her if her defense is almost impenetrable? I mean, it took Bege planning to traumatize her to even make her susceptible to damage, and any attack we saw on her were all fruitless because she wasn't even remotely hurt.

Possible, but I dunno with Akainu. Although he can't take down two Emperors, he could deal with Kaidou or Big Mom on his own, but that's provided if they go to Wano and are forced to side with Straw Hats. Could help the Alliance deal with a Yonkou if the Marines are dealing with the other one.

Wonder if Garp would fare better against an Emperor, though, given his hype and all.
~

But that's all a bit off-topic, so to try and get things back on track and speaking of Yonko...

What if this "Rocks" talk was brought up to foreshadow Kaido and Big Mom actually teaming up?

Do you guys think that would be cool, or would you prefer to have each Yonko do their own thing and remain an individual faction?

At this rate they might really end up together and after finding One Piece they'd be dubbed King and Pirate Queen ...

Also as it was pointed out, if Kaido and Big Mom allied forces, they would also have Wano to back them up, and then what?

All Yonkou (except BB) would gang together/side with Luffy against the WG or something? Can't say I like that idea but I'm just spitballing here.

I can't say I'm looking forward to seeing Yonko team up. With the Supernovae it's one thing I guess, everyone is trying to make a name for themselves for better or worse, but with the Yonko it's different since they're all notorious figures who already control the New World, so it seems a bit unnecessary...

But if Kaido and Big Mom were really part of the same crew at some point, then that's definitely interesting and something to look forward to.

Maybe that's why they "promoted" Luffy to Yonko as well? That way we'd have 2 working together + 3 on their own.

Either way, with the Shichibukai system soon to (probably) be abolished, I wonder if the same thing won't happen to the Yonkou as well.

After Wano and if a Yonko is utterly beaten, well... will they still be considered a Yonko? Will they still hang around knowing that others will probably get to One Piece before them? Is there any interest at all in keeping them around after they've been beaten?

So how likely is it that they get killed for real? Maybe BB sneaks in at the last minute and delivers the finishing blow to one of them or something, maybe.

Because Kaido/Big Mom getting beaten and then trying to make Luffy reach Raftel/become Pirate King seems like a big, big stretch. Not sure I'd want to see that happen.

I mean with Big Mom it would kinda be okay since she's pretty much a grandma and be all like "yeah sure whatever, go get 'em, I'm too old for this crap anyway" or something.

Just some rambling thoughts, sorry

I don't think they'll work together, we saw how Kaidou reacted, and how Big Mom was hoping to recruit the giants to help her beat Kaidou. I think in this instance, they were only friendly due to circumstances, specifically Big Mom wanting Luffy's head while Kaidou owe her a debt. Based on the context, it seems they were either on the same crew, or Kaidou was a random that was saved by Big Mom. Given how Kaidou was said to be from the same generation as Shanks while Big Mom came from the same generation as Roger/Whitebeard, perhaps Kaidou was to Big Mom what Shanks was to Roger.


I don't know if Roger beat them, but he did get their Poneglyphs, and it still didn't stop them from becoming Emperors. Luffy or someone else beating them probably won't either as long as they still have power to back up their status. .

I wouldn't even say he was owning Akainu. I mean, it was very a very emotional scene, you could see how sad and angry Whitebeard was. But objectively, I would even go so far and say that Akainu won that clash. Sure, Whitebeard knocked him out for a few minutes, but the prize was that he lost half his face, an injury that would have killed him if it weren't for Blackbeard's killsteal. And Akainu took that prize in an instant. Halffaced Whitebeard didn't have enough strenght left in him to finish Blackbeard, while Akainu steamrolled Ivankov and Inazuma, faced all of the remaining Whitebeard Commanders, plus Crocodile and Andre, and defeated Curiel and just ignored the rest while continuing after Luffy.

Oda said if Akainu where the protagonist, he would find One Piece in two years. Due to that, I believe he is stronger than the Yonkou or would quickly become stronger than them if he chose to challenge them.

Akainu blowing up Whitebeards face was also so symbolic because he destroyed his white beard. Whitebeard was Akainu's victory.

You have a point there, but I'm not sure if missing half of his face was enough to kill Whitebeard. Dude probably took in too much damage after Blackbeard's crew started attacking him mercilessly that he couldn't do anything else.

Whitebeard cannot be used as he was in a league of his own. Admirals and Emperors equally got handed by him when they fought him.

Only Admirals have gone after Emperors and Emperors need be able to fight with Admirals to advance. The Manga pretty much implies outside of Roger and Whitebeard, they're relatively as strong as the other. Roger and Whitebeard were just leagues ahead of everyone else.

I don't remember hte manga stating the admirals have gone after Emperors, but at the very least, the Emperors do need to have enough strength to compete with admirals, if not make sure their crews can compete with the Marines.

 

[Tonix]

Wait wait wait.
Moria, Kaido and Big Mom were part of a crew that ruled the seas before Roger, and Garp is a hero because he disbanded that crew by either killing or capturing their captain?
I just wonder who might be this infamous pirate... maybe he was still in level 6?

Also, I just noticed that Kaido is a male and interacted with Big Mom...

"Tormund: I want to make babies with her. Think of them... great big monsters. They'd conquer the world."

Not sure where you are getting the idea that Moria was part of their crew. As far as I can remember, rookie Moria clashed with Kaido upon entering the New World and Kaido murdered Moria's entire crew, which is why Moria decided he needed to spend years creating an army of powerful zombies.

 

[Hannibal Psyche]

I don't remember hte manga stating the admirals have gone after Emperors, but at the very least, the Emperors do need to have enough strength to compete with admirals, if not make sure their crews can compete with the Marines.

It was Garp and Sengoku going after Shiki, Roger and Whitebeard. That is more or less Admirals going up against Emperors.

Chinjao said to become Pirate King, one must be able to defeat both Emperors and Admirals because they're equal in strength. Those are the 2 highest degrees of power within the world of Piracy and in the Marines.

If Big Mom wasn't an Emperor and had been sold to the Navy, it's stated that she'd have become either Admiral or Fleet Admiral.

They're evenly matched entities. Only thing the Emperors exceed the individual Admiral is most likely in man-power.

As the latest chapter even implies, Admirals are the ones who go after Emperors which is why we see Kizaru intending to go Wano.

 

[Eigengrau]

I really want that "lifelong debt" to be backed up child support for Katakuri/Oven/Daifuku.

I thought I read somewhere that Kaido is from the same generation as Shanks (who currently is 39), so even if we assume him to be 50-60 (unlikely?) that seems really unlikely considering that the triplets are 48 years old, right?

If he was like 18 at the time of their birth, Kaido would be 66 now, just 2 years younger than Big Mom and I honestly don't see that being the case.

 

[keeper1h]

Not sure where you are getting the idea that Moria was part of their crew. As far as I can remember, rookie Moria clashed with Kaido upon entering the New World and Kaido murdered Moria's entire crew, which is why Moria decided he needed to spend years creating an army of powerful zombies.

At a certain point, a zombie states that Moria fought on par with Kaido, and then he killed his nakamas... so they met more than once.
And for Kaido being so weak to be matched by Moria, that must have happened decades ago...
So I always pictured them like Buggy and Shanks: ex nakamas of an infamous pirate crew, now captains on their own.

 

[Hannibal Psyche]

Moriah isn't really weak. Luffy was easily able to overwhelm Oars with 100 Shadows. Oars was so strong the entire crew.

Moriah also had a massive crew too of whom were talented, how talented? Well, he said only Zoro and Sanji were pretty talented which could mean he had 100s of subordinates equally as strong as Zoro and Sanji pre-skip since he said they were famous in the New World.

This means 100 shadows may even surpass the 100 shadows Luffy consumed because all shadows are not equal. If Moriah had a crew with 100s of Zoros and Sanjis, we can only imagine just how strong he was.

His ability is pretty formidable if he has High Quality Shadows to consume. I don't think it's farfetched to believe that Moriah was able to take on Kaido at one point.

 

[M3J]

Wait wait wait.
Moria, Kaido and Big Mom were part of a crew that ruled the seas before Roger, and Garp is a hero because he disbanded that crew by either killing or capturing their captain?
I just wonder who might be this infamous pirate... maybe he was still in level 6?

Also, I just noticed that Kaido is a male and interacted with Big Mom...

"Tormund: I want to make babies with her. Think of them... great big monsters. They'd conquer the world."

If the captain is older than Big Mom or Whitebeard, he'd have to be dead by now, especially if he's been in jail for decades. But perhaps he was one of the prisoners who escaped when Blackbeard invaded Impel Down, if not possibly join the crew. Would say a lot about his toughness.

It was Garp and Sengoku going after Shiki, Roger and Whitebeard. That is more or less Admirals going up against Emperors.

Chinjao said to become Pirate King, one must be able to defeat both Emperors and Admirals because they're equal in strength. Those are the 2 highest degrees of power within the world of Piracy and in the Marines.

If Big Mom wasn't an Emperor and had been sold to the Navy, it's stated that she'd have become either Admiral or Fleet Admiral.

They're evenly matched entities. Only thing the Emperors exceed the individual Admiral is most likely in man-power.

As the latest chapter even implies, Admirals are the ones who go after Emperors which is why we see Kizaru intending to go Wano.

Oh, I thought you were talking about the current Yonkou and admirals. But yeah, that'd give us an idea of how strong Garp and Sengoku are (or were) if they went after the three Emperors multiple times and still lived to tell the tale. Wonder if the tide of the War would have changed if Garp and Sengoku joined the fray rather than wait until Luffy was close to freeing Ace.

As far as I recall, Roger was never said to have defeated the Emperors or Admirals, just that he managed to survive his skirmishes with Garp even when cornered and got to the Poneglyphs in Big Mom and Kaidou's territories and heard the messages. Again though, feel free to prove me wrong with pages without anyone's interpretation but Oda's.

That would be debatable, were Sengoku or Garp big enough names back then? If I recall correctly, Garp turned down promotion multiple times. What do you mean by man-power? Group vs. group? Because we don't know who would be under individual admirals and how they decide.

Which is still pretty rare. I think the Revolutionary Army and the Straw Hats are probably the only groups who have no problem with going after the Marines or World Government, even the Emperors avoid going after admirals or pissing them off unless they have to.

I thought I read somewhere that Kaido is from the same generation as Shanks (who currently is 39), so even if we assume him to be 50-60 (unlikely?) that seems really unlikely considering that the triplets are 48 years old, right?

If he was like 18 at the time of their birth, Kaido would be 66 now, just 2 years younger than Big Mom and I honestly don't see that being the case.

Wasn't that in a novel or SBS that @goldb posted, that Kaidou and Shanks hail from the same generation? If that's true, then Kaidou and Big Mom likely never procreated.

Jaiminisbox is of similar quality to Mangastream.
I think if you want a better quality, the only way to ensure that is to purchase the Viz translation. That one however sometimes uses strange romanizations and translations, since it is meant to be for the american market, which is not familiar with anime/manga at all. Their romanizations and translations are usually quite fitting, but many puns that only work in the japanese language get lost. An example from current arc would be Sarie Nantokanette. Her Viz Name is Sally Isntoinette. Sally is quite far away from the original Marie Antoinette, and while Isntoinette is a possible translation, not a literal one but one that keeps the flow of the word, it destroys the pun. "Antoi" is terrible to pronounce for japanese people, they would always turn it into "Antowa", that's why Oda named her Nantoka-nette which means Whatever-nette.

WEEABOO ALERT

 

[Hannibal Psyche]

Just read the Viz Translation, makes some things clearer.

Kaido: What kind of a joke is that? I refuse!
Big Mom: It's not you I want anything to do with. If I don't take out Strawhat myself, it's a permanent stain on my reputation and he's got something of mine that I need back.
Kaido: I'm the one whose got a score to settle with that kid! If you come this way, I'll kill uou Linlin.
Big Mom: C'mon, let's just get along like old times!

It's not that Big Mom is requesting to work with Kaido, she's just telling him to leave Strawhat to her because she intends to go to Wano. More or less, both Kaido and Big Mom are just arguing about who gets to settle their score with Luffy, not a case of collaborating.

I was wondering why they don't just intercept Big Mom as opposed to going to Wano, but I guess the reason is because they'll never catch up. All they can do is head to Wano and sort things out from there, but they'll be dealing with the unknown. We could very well have both Shanks and Blackbeard involved in the Wano arc at this rate and more so with Shanks discussing with the Gorosei.

Also, the Viz does state the Gorosei to be the highest rank within the Celestial Dragons. The Gorosei don't seem to be as malicious as the other Celestial Dragons or debauched or decadent. As to how CPO went above their heads too, Even Joker's remark is odd... why didn't he just tell Tsuru to let the Gorosei know they'll be kicked off their lofty Ivory Towers? One could argue he's just grouping them as one since they apparently are Celestial Dragons too. How exactly can the CPO go over the heads of the so-called leaders of the God of the OPverse? I'm at a loss. Hopefully, we will get some clarification.

--- Double Post Merged, Jun 11, 2018, Original Post Date: Jun 11, 2018 ---

Oh, I thought you were talking about the current Yonkou and admirals. But yeah, that'd give us an idea of how strong Garp and Sengoku are (or were) if they went after the three Emperors multiple times and still lived to tell the tale. Wonder if the tide of the War would have changed if Garp and Sengoku joined the fray rather than wait until Luffy was close to freeing Ace.

As far as I recall, Roger was never said to have defeated the Emperors or Admirals, just that he managed to survive his skirmishes with Garp even when cornered and got to the Poneglyphs in Big Mom and Kaidou's territories and heard the messages. Again though, feel free to prove me wrong with pages without anyone's interpretation but Oda's.

That would be debatable, were Sengoku or Garp big enough names back then? If I recall correctly, Garp turned down promotion multiple times. What do you mean by man-power? Group vs. group? Because we don't know who would be under individual admirals and how they decide.

Which is still pretty rare. I think the Revolutionary Army and the Straw Hats are probably the only groups who have no problem with going after the Marines or World Government, even the Emperors avoid going after admirals or pissing them off unless they have to.

Well, in chapter 0, Sengoku told Garp to leave Shiki to him while Roger was Garp's.

Spoiler

Roger also defeated Whitebeard which is why Whitebeard said his scar aches anytime he thinks of Roger. Scars only ache when people remember people that either humiliated or defeated them.

1. Prime example is Chinajo. Defeated & Humiliated/Traumatised by Garp and we saw how.
   Spoiler

   
2. Shanks says the same regarding Blackbeard.
3. Even Tamago says the same regarding Pedro who humiliated him.
   Spoiler

   
4. The same is stated when Whitebeard is reminded of Roger.
   Spoiler

   

And we can't forget that Buggy tells us the only reason Whitebeard is only the strongest now is because Roger is no more. Whitebeard was also said to be the first person that was able to match Roger, and he was still the strongest. Roger was in a league of his own. The strongest. He wasn't just lucky. The entire reason Shiki was reckless and couldn't believe Roger was captured was because no one could defeat him.

 

[Fox666]

At a certain point, a zombie states that Moria fought on par with Kaido, and then he killed his nakamas... so they met more than once.
And for Kaido being so weak to be matched by Moria, that must have happened decades ago...
So I always pictured them like Buggy and Shanks: ex nakamas of an infamous pirate crew, now captains on their own.

Doflamingo said Moriah became too weak to remain in the Shichibukai. Indeed Moriah was physically in better shape when he was still a rookie, and presumably he got lazy after his crew was annihilated. His rivalry with Kaido must have taken place between Roger's execution (24 years ago) and when he first meet Hogback (12 years ago) which he was already fat.