Game:Beast

The Beast is being possessed by his anger and paranoia. With Cogworth's help snap Beast out of it with Get Up! and you should have the battle finished in no time.

Strategy
Fight him as you would any other enemy. Sometimes, the Triangle button would show up (the Reaction Comand Wake Up). Press the button. It does more damage then your Keyblade would. Continue to fight him until his health bar is empty. When it is, he will bend down on one knee. The action "Charge" will show up. Tap the Triangle button repeatedly to send light into him. After many charges, red smoke would appear and the battle will end.