Arkady spent his early life in a lab, undergoing experiments the nature of which he still isn't certain of. It changed the way his body processes nutrients: he is no longer able to survive without supplementing his diet with the blood and flesh of other phuzos. Without that element in his diet, he grows more and more tired -- presumably until he dies. When he was released from the lab, Arkady did his best to meet his nutritional needs in a moral way: he has a lot of compassion for other people, particularly those who are forced into desperation by the selfishness of other people.

But as time passed, it became more and more difficult for Arkady to deny himself the comfort of being fully fed. He has grown less discerning about his victims: his own survival is his highest priority. He works as a bland corporate freelancer, which puts him in contact with enough people to easily scout out victims while avoiding suspicion.