Killer is one of my favorite characters. Smart, strong, great fighting style. Any captain would be happy to have him.
But seeing as Luffy never listens (Kidd actually does listen to a certain degree and doesn't always choose the most dangerous route) Killer would have died in Alabasta and that...
Sounds like hype!
Several possibilities regarding who it could be
Hidden Kaido member Ace
Killer or Brooke (hallucination)
Grim Reaper (like Klaubaterman)
What if the Grim Reaper is the lurking legend only showing himself to a select strong few almost at deaths door...
I suppose Loki could be able to win against Luffy seeing as he is a trickster and that's Luffys worst possible match up (Moria, Foxy, Ceasar) as stated by Zoro. We've seen it before that most strawhats struggle against tricksters with Yeti Cool Brothers, Perona, Monet, Law, Miss Valentine and so on.
Kidd will come good. The moment he truly arrives at the top Luffy won't call him "Jaggy" but Eustass or Kidd and it will be the same the other way around (Monkey or Luffy, not Strawhat). It would show that they truly acknowledge one another.
Instead of walk of shame it would be fitting if Luffy set them free upon the condition they work for the benefit of Dressrosa/Alabasta. And if they act up then Luffy, WSM and Pirate King would take them down himself. And even if he was busy WSS Zoro could do it, or Sanji
It will come, they need to save some to sell data books. We are yet to get
And probably some more that I'm forgetting
Information about Uranus, perhaps Momonosuke is Uranus?
Shanks makes his move. Something sinister?
BB steals what he was after, perhaps Big Moms poneglyph? Katakuri dead?
Aokiji tries to stop BB and fails, perhaps 2025 or something like that though.
Kaido defeated by Luffy for the most part...
Anyone can become a monster with Magma or Lightning-fruits, the powers are just that incredible. But that doesn't make for example the Sand-fruit weak. It's up to the users imagination to utilize it's possibilities.
Sand is made out of rock and minerals, what if Crocodile found a way to make...