Original Guide by FUZBY - https://www.playstationtrophies.org/profile/122658/
- Swallow attack. When there is no light in the room/no circle runes in operation, he sends a mound of ooze after Dante. Dante is then forced into battle with an easier version of one of the other bosses of the game, Phantom, Nelo Angelo and Griffon. Damage depends on how the mini-boss fight goes.
- Orbs. Shot at Dante, simple to dodge. Minimal damage.
- Small, moving bits of slime, which turn to crystal on impact. Keep running to avoid. Fair damage if multiple ones attack.
- Spears. Around three at a time. Dodge by running. Deals moderate damage.
- Blue beam attack. Prepares by making his crystal vulnerable and blue beams appear on the floor. Dodge by staying close/behind him. Deals moderate to dangerous amounts of damage. (3rd FIGHT ONLY: This beam lasts up to a lengthy five seconds.)
When you hit the circular runes and the room is well-lit, his sphere will come out of his back and remains vulnerable for a short amount of time. Take advantage of this and slash away at him. Avoid using Ifrit, as it is much to slow for the battle at hand. If you do happen to get swallowed, and defeat the mini-boss inside, he loses around quarter of his life. I used this to my advantage when his life was low. Mini-bosses also have a chance of dropping green orbs, but don’t count on this happening all the time. Also, as suggested by Angry Gargoyle, for Nightmare, it is actually easier to time (with Alastor) for the side spear and boomerang attacks. The deflection stuns him for 20-30 seconds and allows you to do some heavy damage to him when activating Devil Trigger. This is essential for Dante Must Die mode.