Kurt Moller is an experienced slayer with over 989 kills to his credit. The Slayer's Guild sent Kurt to Stokely to slay the Chosen One (Vlad). He was equipped with a UV grenade launcher as his weapon of choice and he viewed the Van Helsings' weapons as antique. At the Chosen One's crowning, Kurt slayed several vampires including Will, Ingrid's half-fang boyfriend.
He, like all the other humans there, had his memory wiped by Vlad at the end of series 2, although, like Jonno and Mina's, his memories were later restored, but unlike theirs it was not the trauma caused by the fall of Stokely which brought them back (he left the place shortly after the mindwipe), but rather when Vlad restored every slayers memory that he's prior wiped himself during series 4.