Talk about a dark presence, Vincent sends chills down the toughest person's spine.  Although he may look evil at first, there's a good soul trapped beneath his dark exterior.  Vincent's plight is yet another example of Shin-Ra's warped experimentation; however, there's more to the story than just bungled scientific research.

Level 1: Galian Beast  Vincent transforms into a purple beast with horns that attacks with fir-based attacks.  Beast Flare-- Launches several orbs that explode and cause damage to a group of enemies.  Beserk Dance-- Performs a combo attack against a single enemy.
Level 2: Death Gigas  Vincent transforms into a Frankenstein creature with powerful physical attacks and a lightning-elemental attack.  Gidadunk-- Hits a single enemy with a powerful punch.  Livewire-- Attacks an entire group with an electrical charge.
Level 3: Hellmasker Vincent transforms himself into a chainsaw-bearing maniac who may look very familiar.  He can attack with his weapon of he can cause several negative status effects.  Splattercombo-- Hits a single enemy five times with his chainsaw.  Nightmare-- One enemy is hit with several status effects including Mini, Frog, Sleep, Mute, and Confusion.
Level 4: Chaos  After aquiring the submarine or a Gold Chocobo, you can reach Lucrecia's Cave, which is located behind a waterfall at a lagoon in the Nibel area.  Visit the cave with Vincent in your party during Disc 2.  Then during Disc 3, revisit the cave with Vincent in your party and you'll get his Chaos Limit Break.  Chaos Saber-- Acts like Slash-All, but doesn't rely on Vincent's weapon to determine damage.  Stan Slam-- A large skull is created under the opposition.  Any enemies that aren't instantly killed are hit by flaming skulls.