Luffy is the only satisfactory option IMO. He's already inherited Aces attacks (or at least his own variant), and from everyone we know of beside perhaps Dragon ( no Garp since his style is void of DF ability) Luffy is the one that has the most in common with Teach to qualify him to be able to use more than one DF being an inheritor of D. How he would combine Mera Mera with Gomu Gomu is beyond me though. I have a few ideas but I would assume there's some kind of paramecia-logia incompatibility.
I also wouldn't mind seeing what Ryoz said. Like Luffy will be goofing around with it and a bird will come and eat it. Then the strawhats would have a PHOENIX!!! With all the mythical creatures we've been seeing recently it would kind of make sense (Dragons, Harpies...). Navy warship fleet you say? Just send the Phoenix
Someone else mentioned giving it to the Sunny Go, which I was considering... Until I realised it would 'Go' the way of the Merry. But it's possible it could just fly everywhere, and it would also make any attack without haki ineffective... It would get kinda hot though...
Then again I think there's the slight possibility Luffy might not care for the Mera Mera fruit at all. It seems expected that he would but its also totally within his character to do the unexpected... For now it's up in the air.
As for THM Nindo's theory regarding where and how it arrived back into the world, I'd agree with him mostly. But MarineFord didn't really seem like a place with much room for vegetation to me. It probably generated on the nearest tree of the fruits species, if not MarineFord then definitely an island nearby
are you guys seriously thinking luffy will eat it? i just checked for the record, Luffy saw Ace use the mera mera no mi, 2 times, once vaguely when he destroyed a warship, once when saved him from aokiji right before his death.
There is no possible affection or connection for luffy to the mera mera no mi
But I agree with you, the more I think about it, the less I think it will be Luffy to eat it. It just...doesn't seem to fit and he already has the ability to fight with fire.
In my opinion it cannot be Zorro or Sanji, they have a rivalry were they are very close to each other in power (I personally think Zorro has the edge). Either one of them gaining a devil fruit ability, specially that of a Logia like the Mera Mera would shatter that rivalry putting one clearly beyond the reach of the other.
So we have ..
Franky - VERY unlikely in my opinion as he already has enough power.
Nami - Possible, Fire Storms?
Ussop - This is my favourite option as would like to see what he could do with his accuracy. Paired with the Mera Mera he could shoot fire at stupid range with ungodly accuracy (only problem I have with this is that it pretty much negates his bag of seeds he worked so hard for)
Kimemon - Don't see him as part of the crew yet, although it's possible
Rest have df's already and if I remember right, eating two makes you explode (other than Blackbeard).
Random Person... Unknown
no intend to spoil anything but
just a theory
Now that Zoro's sword has been stolen ( a nice excuse to get in the arena), i think it's possible that he will finally get the flaming sword of his dreams... i would be satisfied, personally i don't give a crap about Coby, i don't want to see him with the same powers as Ace.
What purpose does a sword have if it does not cut? Besides, Zoro already has an attack that ignites the opponent.