How to Beat Cerberus in Kingdom Hearts

Equip healing items. Make sure you have your whole party equipped with potions. If you have stronger health potions such as Hi-Potions or Mega-Potions, that is better.^[1]

Prepare your friends for battle. Set Donald and Goofy’s item actions to “Only in an Emergency” so that they will just use health recovery items when they reach their critical health level. This will save you a lot of health recovery items.

Save before the battle. There’s a save point inside the coliseum lobby. Make sure you save your game state there so that (just in case you lose the battle) it’ll be easier for you to try again. This way, you’ll get to resume your game inside the coliseum lobby already!

Enter the arena. Once you are ready, choose “I’m not afraid” when you are asked if you want to enter the match. Once you agree to step inside the arena, there will be a cut scene. The battle commences right after this short cut scene so be ready!^[2]

Lock onto one of Cerberus' side heads. Immediately lock onto one of Cerberus' side heads. Right side or left side, it doesn’t matter - but do not lock onto the middle head just yet. When he starts hurling energy balls at you, dodge by rolling out of the way. When Cerberus roars at the sky, he will start to bite attack...this is your chance to attack him! Approach him and attack the side head you locked onto. Attack very little at a time, then distance yourself. If you don't, Cerberus will do a powerful bite attack on you.^[3]

Dodge a lot. You cannot attack Cerberus continuously. You will need to attack in short bursts and then get away by doing dodge rolls and jumps away from Cerberus. Just keep in mind that Cerberus will surely interrupt your barrage of continuous attacks, so don’t attempt to do that.^[4]

Use health recovery items wisely. When your health bar is flashing red or about to be, immediately run away from Cerberus and use a recovery item. Do not use your recovery items on Donald or Goofy since they have their own recovery items. Besides, even if they get knocked out, they will auto-revive after a while.^[5]