Vamp is initially seen as a member of the group Dead Cell/Sons of Liberty, led by Solidus Snake, who capture the offshore “decontamination facility” Big Shell (In fact a cover for the development of the Arsenal Gear). He is first seen making short work of a SEAL team. Vamp, as the name indicates, has various Vampire-like abilities, including a taste for blood, and the ability to levitate, as well as superhuman reflexes.
He also has uncanny healing abilities, giving off a sort of immortality, not unlike a Vampire, and he encounters operative Raiden several times, including once with a Harriet Jet (Co-piloted by Solidus) . Although at least one bullet to the head leaves a permanent scar. He also shows extraordinary skill in knives, which he uses to fatally injure Otacon/Hal Emmerich’s stepsister, Emma Emmerich.
Which, while sad, at least gave us these badass moments afterward.
Although presumed finally dead at the end of MGS2, he shows up in the ending, shadowing Snake and Raiden in Manhattan (In front of the car there).
Vamp however later resurfaces as part of Liquid Ocelot’s Beauty and the Beast Unit 5 years later, where he is trying to keep Naomi Hunter detained. However, during their attempts to escape (In which Vamp also has a few “deaths”) he has an epic rematch with Raiden-which both survive, although with Raiden heavily damaged.
Once Naomi is ‘rescued’ she reveals Vamp’s unusual abilities are in fact, not supernatural, but artificial-the result of Nanomachines giving him superhuman abilities. Naomi seems to later rejoin Ocelot and betray Snake’s team.
However, Naomi provided Raiden and Snake with a way to defeat Vamp-by suppressing his nanomachines, weakening him enough for Raiden and Snake to defeat him. Finally, Naomi herself gave Vamp a more potent serum which eliminated all his nanomachines, finally killing the immortal. Naomi compared herself to Vamp, since her cancer had also been suppressed by nanomachines, and therefore like Vamp she was living on stolen time, and was sort of ‘undead’ herself, and then deactivated her own, killing her. Otacon grieved both for her, but also didn’t feel any better when Vamp died despite his role in his stepsister’s death.
It should be noted that Vamp is voiced by Phil Lamarr, who played Marvin in Pulp Fiction, but also has done many, many voice acting roles as well as several roles on the sketch comedy MadTV.