Zeref isn't weak, not at all.
People here hate him because he was defeated by a Natsu with wild, emotional flames, who drew his power from the guild mark... and people interpreted that as "Base Natsu".
It's a bit of a hatred that's lingered since the end of the original series because many people hate that Natsu had to fight him alone... And as soon as you fight or lose against Natsu, people see you as scum. It got worse with Jean Grey constantly using the image of him getting one-shotted by Natsu in FH mode.
It's a bit like he was harassed for disappointing people in the final arc... Which is pretty unfair, honestly, he's no more disappointing than any other antagonist. Besides, during the 2017 fighting tournament, people were seriously arguing that Invel or Laxus could beat him :
Yeah I thought that too, that they are only saying that because of his last battle and yes, his battle was probably the most disappointing battle in the whole franchise but that doesn't mean he is weak.
No way Invel and Laxus from the Alvarez arc could defeat him. Probably not even the current Laxus could defeat him. People forgot that Zeref not even used his main power the death curse in his battle in a good way like he did before the Alvarez arc. I think because Mashima wanted to end the manga so he rushed the battle, plus Zeref wanted to have "fun" in the battle.
We saw in the Aldoron arc that a Zeref seed could damage Aldoron with the curse and Aldoron was afraid that he could die if he doesn't stop the Zeref seed, so Zeref is maybe the only one (with Mavis) who could defeat/kill dragons without DS magic. With the except of Acnologia who is immune to magic. But in theory he could even defeat/kill other dragon gods like Ignia, Selene, etc. That doesn't means he is stronger than them, but his curse is such powerful that he could kill for sure 99 or 98% of the whole cast if he really wants it. Same with Mavis btw.
In his FH Mode he is maybe even stronger than the DG? Maybe not, who knows, but his curse with unlimited power should be enough to spam his spells over the whole world, but again, only in theory without the bullshit Mashima showed us.
Zeref Dragneel - Invel Yura Voting Rules: This Battle is a 1 vs 1. During the Best of 16 knockout stage, you'll be able to vote up to 24 hours after discussion ends. You may vote for one character in this fight. So you voted early and someone/something changed your mind? You can use the...
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Laxus Dreyar-Zeref Dragneel Voting Rules: This Battle is a 1 vs 1. You may vote for one character in this fight. So you voted early and someone/something changed your mind? You can use the 'Change Vote' option to choose again. Discussion and Voting ends: June 5th, 2017
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And with this harassment and the agenda working against him, he lost to Irene, even though Alvarez arc explicitly told us that Zeref is stronger and more skilled in magic than her...
https://mangahelpers.com/forum/threads/zeref-vs-gildarts-vs-irene.3008195/
Lol thats ridiculous, it was shown that Irene is someone who hates to get orders from others, and even if she was arrogant, she was not dumb, she wanted to fight August because he gave her orders maybe because she saw him on the same lvl and not above her? In the way how Irene was shown us, I don't think she would accept someone above her if the person is not stronger/more powerful than herself. Thats why August and Irene were on the same lvl. Only Zeref was above them.
And even if Irene and August could use magic/spells with more destruction power like Sema, Ars Magia, U1, that doesn't mean Zeref is weaker.
Even though I wish we would have seen some spells from him too with extreme destruction power.
But his curse is more then enough to defeat both August and Irene.
I can understand that people think that Irene and August are stronger because we got some good feats from them, and arguebly they were better potrayed than Zeref especially Irene got a lot of screentime and focus in the last arc, probably even more than all other enemies in the arc?
But there is nothing what they can do against Zeref. Zeref can use enchantens too (maybe not on the same lvl like Irene but still), he can use dark arts, like the one spell to stop the time, what he used against Natsu in the Tartaros arc to talk with him. A spell that he doesn't used in his last battle. He can use Nemes like Hades it did, he could use some other black magics, etc.
People forgot that Alvarez arc was rushed af, many things doesn't make sense same with the 100YQ but yeah, we can't change it.
In a way, there's a hatred for "soyboy" , and that's why I think Jellal is just as underrated like Zeref. Because when he comes back, he cries for his crimes quite sincerely, but people interpret him as a "wimp." Not to mention all the harassment he endures because people hate that he's in a relationship with Erza because they think she's "too good" for him, or the power scaling, the way people say he's weak, that he loses against X or Y... (To be honest, the way Mashima treats him encourages people to think that way, just like with Zeref). And the worst part is that if you defend him or say he's stronger than people think, you'll be called "overrated," even though that only comes from a minority of people.
Some people are strange lol
Everyone who reads shonen should know that the authors give af about power scaling. They often write characters how the story needs them. Also, only if someone lose to characters Y doesn't mean that he/she is also weaker than character X or would lose to them too. In the case of Jellal, if he as example lose against Misaki because of her hax or against Haku, just like Natsu and Lucy, doesn't mean he would also lose against Kirin or Suzaku. The abilities of the characters are important too. Not only the power lvl. Plus plot armor, etc are also important. Thats some of the reasons I don't care about power scaling anymore.
One of the best examples is Erza vs Mdnight during the OS arc, she used her brain and her abilities in a way that Midnights magic could not effect her. Erza is powerful but, would she have fought against another OS member like Racer or Cobra she would have more struggle against them than against Midnight and that although Midnight was the strongest among the OS.
Same can be said about other enemies too, like the 9DG, Erza won against Kyoka, but maybe she would have lose against Torafuzer, Keyse or Silver.
Or the S12, Erza would have much more trouble to defeat characters like Dimaria, Brandish, Invel, Bloodman and God Serena than Ajeel. Same with Jellal, he could defeat characters like Ajeel or Wall, but against characters like Dimaria, brandish, Irene he would lose or have extreme trouble to defeat them (especially without plot device).
It's also often a situation and opponent thing. So it often doesn't make sense to judge and to think which character is stronger or not because it's not only usless in some situation but it also doesn't mean anything, because most of the main cast characacters (main characters and important side characters) are often on the same lvl (who cares if someone is slightly stronger or not?) the same with the enemies like 9DG, S12, BDSK, DG, yeah, some of them are stronger than the others in the group and the gap is probably a little bit higher than the one from the good side, but they are still all approximately on the same lvl.
There are enough examples in FT and other shonens and people are ignore them because of their own agenda.
My post was long, sorry, but it's to say that even if Zeref has flaws in his final execution, his development and backstory are very good, and I think the same goes for Jellal; he undeniably has flaws in his character development, but I like how he was a poor boy who came from nothing, wanted to be strong for his mum, got captured in ToH by seing his mom dying, and revealed his powers with Ultear's brainwashing and his attempt at redemption, which Hiro completely botched because he only wanted to focus on the main heroes...
It's okay, my post is now also longer than I thought it would be
I agree in everything.
Imo people should differentiate between power lvl and the personality of a character. I often see that people hate characters because they are weak, or because they got a bad treatment, etc. I always wonder, why? What has the battle or the power lvl to do with the personality, design, abilties or development from the chararacters?
Zeref is my favorite character because of his personality, because of his backstory, the development, the ability. He is imo a really well written character, with some flaws yes, but still one of the best ones.
Did I hate the final battle? Absolute. Did he get a really terrible treatment? Hell yes, but because of that I don't hate him lol
Same with Jellal I like him because of everything we saw from him. Even though I must say, I liked him still more, when he was a villain. But don't hate him or something like that, but I can see why some people say he is boring or anoying because almost everthing is connected with Erza and Zeref. But like with Juvia, it would be really nice to see him with other characters, in his case I wish we would get a team battle with Lucy.
Hiro did a good job with many characters until the Alvarez arc. This arc was like I said rushed af. Many things were not even showed.
Like the reasons why the S12 even work for Zeref, some of them, if not even all of them, knew who he is, so why is someone like Brandish on his side?
What was the reason behind Crime Sorciere if no one of them was part of the battle against Zeref?
And some other things.
But imo even with the mistakes, flaws, etc, Hiro did still a great job, even in the last arc and even in the 100YQ. Because of the short battles I think people don't see that compared too other shonens, Hiro still use many of his characters and often in a good way.