@AtARU:
I'm not really against having a tournament but I'd just rather see Luffy taking the stage, grabbing his brother's fruit and just saying something like "This is mine". The SH would proceed knocking out challengers, Doffy's crew included with Conqueror's haki wiping out half the Colosseum, the other half getting absolutely destroyed.
It's about damn time for the SH to take main stage. No remote islands, covered up events or phone threats… I say this because territory in the New World is a big issue. If Luffy wants to claim territory for himself and be taken seriously he'll need to prove his "badassery". I know this is bound to happen once he takes out a Yonkou but it I'm in dire need to see the SH going ssj2 and showing us (and the New World) how big did they really get.
Like Zoro said "The new world starts here" but Oda hasn't really shown us big threats or powerups (haki aside). The SH should be show making an even bigger name for themselves and earning some pirate cred and this should be a great chance to do so give that a lot of big names from the NW are there. But given the introduction to Doffy's gladiators I don't see an all out brawl happening anytime soon.
Wait, so you want big threaths, but at the same time you also want Luffy to knock everybody out in the Coliseum with CoC. This is contradictory.
Also, the same thing happened during Fishman Island. You want Oda to repeat himself?
Luffy couldn't even make the Fishman Pirates Officers faint with his CoC. He's not taking half of the Coliseum contestants out with a single blow.