Zemarkhos brought Vaspur with him when he confronted Gagik Bagratouni at the latter's home over a misguided attempt to convert the Ronams to Phos-worship. He threatened Onomagoulos and his guards with Vaspur but they were ready for him. One guard threw a sack over Zemarkhos and knocked him to the ground. A second seized Vaspur and while dog tried to bite him, he could not chew through the man's gauntleted arm. He forced Vaspur into the sack with his master. Upset, the dog began biting Zemarkhos and would have killed him if Marcus Scaurus had not intervened and convinced Onomagoulos to spare him.
After his master became the most powerful man in the western parts of Videssos, Zemarkhos took Vaspur around with him everywhere. In the end, this turned out to be his undoing. During a trick of Marcus Scaurus and the ensuing riot, the dog turned on his master and bit him in the throat, killing him.