My speculations are:
Luffy: Whether or not he will get another powerup besides mastering CoA depends on how much work the other Supernovas, Yamato, and maybe Marco put in against Kaido. If he does get one, it could be G5.
Zoro: Depends on how strong Enma Asura Zoro is, but he could also improve his Haki during his fights.
Sanji: Depends on how strong RS + DJ/HM is, but Sanji could also improve his Haki.
Jinbe: No power up since Jack has already been weakened for him
Franky: If he's gonna beat Sasaki in round 1, then he will awaken CoA mid fight probably. If he loses and then comes back for round 2, he could incorporate seastone into his metal body in order to make his punches stronger overall and effective against DF users.
Brook: Can't think of anything except Haki or Awakening
Robin: Same as Brook
Chopper: Same as Brook
Nami: She will obviously get Zeus back, but maybe she could also steal Prometheus by feeding him heat balls. Also Haki.
Usopp: Besides Haki, maybe he could steal some of Queen's plague bullets.
Luffy: Whether or not he will get another powerup besides mastering CoA depends on how much work the other Supernovas, Yamato, and maybe Marco put in against Kaido. If he does get one, it could be G5.
Zoro: Depends on how strong Enma Asura Zoro is, but he could also improve his Haki during his fights.
Sanji: Depends on how strong RS + DJ/HM is, but Sanji could also improve his Haki.
Jinbe: No power up since Jack has already been weakened for him
Franky: If he's gonna beat Sasaki in round 1, then he will awaken CoA mid fight probably. If he loses and then comes back for round 2, he could incorporate seastone into his metal body in order to make his punches stronger overall and effective against DF users.
Brook: Can't think of anything except Haki or Awakening
Robin: Same as Brook
Chopper: Same as Brook
Nami: She will obviously get Zeus back, but maybe she could also steal Prometheus by feeding him heat balls. Also Haki.
Usopp: Besides Haki, maybe he could steal some of Queen's plague bullets.
