Chasm

Story related; cannot be missed.

Ulak is the final boss of the game located deep within the Magma Chamber. There is only one save room halfway through the chamber, so if you feel you are not prepared, get back to town and stock up before saving (a Warp Scroll is useful here). His attacks include hands that reach up through the floor and tentacles that splash lava, green orbs that spawn in various patterns, a laser beam attack, and an arena floor that will break away as you whittle down his health. You can only strike him when the eye is open and you have to jump up to get a hit in. Magic Shield can help to get extra hits. Upon killing him, this trophy will unlock.