Gunn (Charles Gunn) first appears in Warzone he sees Angel beating up a blackmailer and then tries to actually dust Angel without success, he at first does not trust Angel for what he is but eventually realises that he is no ordinary Vampire. The leader of the gang that keep their neighbourhood clean of both Demons and Vampires (and whatever else emerges from the depths) an unknown, and uncalled "Slayer". Together with his band of fellow deadbeats, they patrol the streets of the less well favoured areas of LA hunting down vampires and their nests, he is strong willed and will never let anyone order him around. After his sister is taken away by Vampires he ends up dusting her which leaves of course permanent scars. He eventually realises with a little help from Cordelia that he has many demons himself he must defeat so that he can come to terms with what has happened in the past.
He becomes a regular cast member from the start of season 2 even gracing his presence on the opening credits, he assists Angel in a number of cases one which started off as his own when they defeat the Demon Deevak
I am sure that Gunn will continue to be a great friend and fellow fighter of dark forces for Angel, Cordelia and Wesley.
Gunn: "Whoo-whoo! My god! They told me it was true, but I didn't believe them.
Damn, here it is! Evil white folks really do have a Mecca. Now, now, girls, don't
get all riled up. OW! Did you just step on my foot? Is that my foot you just stepped on?
Are you assaulting me, up in this haven of justice? Somebody get me a lawyer -
because my civil rights have seriously been violated. Oh, I get it, I get it. You
all can cater to the demon, cater to the dead man, but what about the black man!"