Guhhrahk
You need to use Toa for defeating Gurrahk, Matoro for beating Guhhrahk Hajli and Jaller for the summoned enemies.

Easy Lego pieces
How to: Go to Roodaka and hold X when you fight her. After you get Hero mode, use a piece of tape to keep X held on the controller so you can keep attacking. Use Hahli, Vezok, or even Vezon so that they keep shooting streams to easily defeat the summoned Visorak. When there is a villain your character will lock on automatically and kill them then switch to the next because of the auto-aim. Your character does best in Hero mode and is unlimited, you can easily gain Bolts.

Vezon Unlock
How to unlock: If you want to Play as Vezon then finish the game.

Vezon
You will have to fight Vezon for the last time after you defeat all Piraka. First hit him in the back, then legs, then heads.

PS2 Cheats for Bionicle Heroes

Bionicle Heroes cheat codes

Bionicle Heroes cheats