A lot of people find Setzer useful for one thing. They use the pause feature to hit the kills all enemy slots combo every time so they one round win all of their battles making him useful. To me he is third most useless in the game ahead of only Relm and Gau. Relm is flat out useless and the glitch with sketch is plain annoying and Gau well i just don't want to spent 12 hours trying to get all his friggin rages and then not have the rage use the proper ability when I need it so he stays in the airship for kefka's tower.