Rudi Wenders (ルーディー・ベンダース Rūdī Bendāsu) the "Nidhogg" (ニーズホッグ Nīzuhoggu) is a human who becomes an Eater (alongside his childhood friend Theresia Riefenstahl) in order to kill vampires and eventually take his revenge upon Theodosius M. Waldstein. To achieve this end, he and Theresia join The Organization.
In 2005, he and Theresia are dispatched to the island of Growerth alongside Zygmunt Kiparis and accompanied by Melhilm Herzog. There, Rudi encounters Theo and the two have a eventful confrontation. As a result of the encounter, Theo overexerts himself fatally.
His life is saved by Garde Ritzberg, who subjugates Rudi's cells and makes him his new sworn follower (much to Rudi's distress).
After Theo betrayed him, young Rudi loathed all of vampirekind and believed fervently that humans and vampires could not live harmoniously.