Slayer is a playable character in the Guilty Gear franchise, who made his first appearance in Guilty Gear XX. He is the first, and so far, only vampire in the Guilty Gear series. A charming, refined and somewhat erudite man, Slayer exudes class, but that is not to say he doesn't enjoy combat. Although he is technically not a part of the on-goings of the Guilty Gear world, he often offers advice to other characters, and has grown somewhat attached to their world.
Slayer founded the Assassin's Guild, but disappeared shortly thereafter. His original intentions, like many notable founders of Assassin's Guilds in fiction, were altruistic. Unfortunately, he finds, upon returning, that his syndicate is far from his original idealistic view of it, and decides to dismantle it. He seems to be connected to Gabriel in some significant way, and seems to know quite a lot about various political affairs, most notably the Post-War Administration Bureau. Slayer is married, his wife a woman named Sharon. They appear to have a good relationship, as she appears by his side in several of his poses, as well as his endings. She also seems to be a source of blood for Slayer.
Slayer is also a descendant of Nosferatu. With his unyielding attacks and special vampire abilities, he makes mincemeat of his opponents in minutes. When his old organization now in chaos as a result of Zato-1's absence, Slayer emerges from retirement to "tidy" things up.
And he is reprised by J. B. Blanc in the English dub and Takaya Hashi in the Japanese dub.