Fulfill certain conditions in the Battle Coliseum mode to unlock these characters to use within that mode. Some characters have multiple conditions to fill; in this case the different conditions will be separated with a semicolon. Conditions involving winning matches with certain characters can be done with or without a teammate.

Character	How to unlock
Ace	Clear 5 Battle Royales; Perform 1 Link Attack.
Brook	Win 2 Fights with Sanji and a female character.
Chopper	Earn 1st Place in C League.
Crocodile	Perform 15 Dodges with Hancock; trigger 5 Item word effects.
Franky	Perform 6 Counters with Zoro.
Hancock	Clear 3 Scrambles.
Jimbei	Perform 8 special attacks with Ace; Perform 20 dodges with Ace; Perform 2 link attacks with Luffy and Ace.
Nami	Clear 2 Duels.
Robin	Clear 2 Battles with Nami.
Sanji	Get Promoted to B League.
Usopp	Earn 1st Place in C League.
Zoro	Get Promoted to B League.