Make some attacks for the characters and describe what they can do (all names do not have to be in JAP).
like luffy can get a "gomu gomu no tornado" where it is like a fast spinning twin mucchi with hands in the air or ground
Sanji can get like "Grand Slam" where he shoots something into the ground with force
Zoro can get "Guilotine" where he attacks frm the sky with one sword to cut the enemy down to size
Nami Flame tempo: Flamethrower or Fire hoops fire hoops are three rings of fire that constrict an enemy.
Usopp: 6 axis hissastu phoenix star: send six burning phoenixes to the opponent
Robin: Body Armor: Similar to Wanze's noodle body but with hands.
Chopper: Rumble Speed Point : has stronger and faster legs and bigger horns
Franky: Coup De Blast: Uses both hands two send half powered coup de vents put them together and you get a full powered coup de vent
That's all I have and sorry can't think of anything for brooke