Bruce is a villain in Kingdom Hearts II ½.
Role
A mighty great white shark, Bruce is actually not very villainous. He's trying to become a vegetarian, but goes into a raging feeding frenzy whenever he smells blood. Nilmax and Xerruy use this to their adventage and use the darkness in his heart to control him, hoping to turn him into a Heartless. After Sora, Marlin, Donald and Goofy defeat him and release him from Nilmax and Xerruy's control he offers to be their friend.
As a Boss
Bruce is essentially an overpowered version of Glut from Atlantica. He is capable of devastating biting combos and often charges across the arena, ramming anything in his way. He is very fast and agile, but his great sizes makes him relatively easy to hit. Occasionally, he'll try to swallow Sora - use Escape to prevent this. If this fails, Sora will still manage to break free from Bruce's massive jaws, but not without losing a great amount of HP. Due to the superconductivity of electricity in water, Thunder magic works very well against Bruce.