Well, if we want to guess what’s to come first we have to consider hints and foreshadowing we have been given so far.
The things so far foreshadowed that are likely to involve the Strawhats are.
- Fishmen Island Destruction
- Reverie
- Big Mom
- Fishman Island under a Strawhat Flag
- Wano
- Doflamingo
All those are in order that they were revealed to us in the manga. It’s not chronologically ordered.
Now if you sit down and actually think about these things and try to chronologically order them I think you’d come to a reasonable guess.
I’ll give you my list of how all this will occur chronologically, I’ll explain my reason after ordering them.
- Big Mom
The next three are in my opinion all in the same arc. Any one of them can occur before another. So it really doesn’t matter how you order them since I believe it’s the same arc.
- Reverie
- Doflamingo
- Fishmen Island Destruction
- Strawhat flag Fishmen Island
Lastly, from what we got is Wano.
Last. Wano
OK, reason for Big Mom being resolved first.
Luffy’s has so many things to resolve with her which are the most important to be done imo before anything else on this list.
First and foremost is Jinbei. He would be in the crew atm if it wasn’t for his duty to Big Mom. I don’t think he will miss out on adventure with the strawhats to a place as important as Wano.
Second, the tea party which is in 3-4 days. Luffy’s sent a treasure box which is full of explosives. Luffy’s already a locked a target of BM and this treasure box will only hasten and increase the tension between their unavoidable clash.
Third, Captain Kidd, He has already targeted BM and now his got an alliance. Obviously he will be involved in this fight against BM.
I know what you’re thinking… How does this show that Doflamingo or Wano won’t come first… I’ll get to that, bear with me please.
The return to Fishmen Island.
The most important thing we should ask ourselves is why would Luffy go back to Fishmen Island and possibly when? And what will happen when he goes back there? If you think about this then you’ll get your answer.
Reasons for returning to Fishmen Island are.
The defeat of BM.
BM has already said that she has now turned her anger towards Luffy instead of Fishmen Island. Also it’s hinted that the Sun Pirates are working for BM. So this can cancel out BM being the one to destroy Fishmen Island. BM’s events have been given very short time line while event’s involving Fishmen island much longer.
The tension between BM and Luffy will only grow further.
Defeating BM will have Jinbei’s official Joining, returning to Fishmen Island for claiming it and will be used as a reason for Luffy’s foreshadowed destruction of Fishmen Island.
It is Luffy who will destroy Fishmen Island like Shirley predicted but off course under Doflamingo’s control.
The things I’m not certain about are.
Will the Reverie occur before Luffy returns to fishmen Island, During it, or after Doflamingo Conflict?
Will Fishmen Island even exist or will they take the Noah to live on the surface Islands after Luffy destroys it.
Luffy will certainly protect any Island the Fishmen decide to live on.
The two things I connect Doflamingo with Fishmen Island are; Luffy destroying it under Doflamingo’s control and Caribou “that person” Doflamingo coming after Poseidon.
The Reverie might take place after the conflict with Doflamingo is over.
Doflamingo comes down to Fishmen Island and tries to take Shirahoshi where he encounters Luffy. Law has history with Doflamingo and an alliance with Luffy so his definitely going to be involved. Like how Kidd and Luffy will be against BM, similarly Law and Luffy againts Doflamingo. After its over we will get a positive outlook on Fishmen Islands future.
Fishmen live on land due to the destruction of its Island. The Reverie might be a good place for Fishmen to come in good terms with the government and human's by receiving help from them. We can have a short Vivi and Shirahoshi talk.This is how I say it's likely to occur.
Ok, Now Wano Is Last, after Doflamingo IMO.
Reasons are.
First, Wano is receiving a lot of hype, as much as Elbaf if not more.
Second, Wano isn’t a place they have a reason to go so far. Helping Kinmon and Momo “might” be one but not enough to actually delay events which are far more important and are on a short time frame. Also remember Wano is a country Pirates and Marines dare not enter. Wano must be super powerful. Kinmon and Momo should be fine on their own; Kinmon came to rescue his son(alone?) he can get out, after the arc is over. There is also the possibility of the Marines lending a helping hand to Momo who is also in need of a health check. The kids under the Marines can have a proper recovery. Obviously Kinmon will follow his son.
Third, BM’s conflicts are on a very short time frame.
Fourth, If BM events don’t come before Doflamingo or Wano than Jinbei will not join for quite some time maybe even years… I don’t see that happening.
Fifth, if BM doesn’t get taken down there is no reason to return to fishmen island, more delay in the prophecy of the islands destruction.
I don't see any of these forshadowed event's happening if BM isn't dealt with.
This is how I think everything will go down, with some minor visits in between each arc I guess.
Edit: Also my guess is Doflamingo won't be defeated in the arc that he will most probably be in at Fishmen Island, or maybe he will.
What I'm getting at is Doflamingo will do to Shirahoshi the same thing he did to Momo(mind control?). I believe he will use her in the future as a weapon for himself, even after this predicted arc is over.