Bartok is a surviving member of the destroyed Gatatog Clan. As one of the last surviving males of Gatatog, Bartok holds a deep grudge toward the Urdnot and wants to bring the clan to it's knees. Bartok himself has a deep obsession with artificial intelligence and the Geth.
Ever since Saren used the Geth to attack Eden Prime, Bartok has been trying to find a way to make his own armies of synthetics. After joining up with the Blood Krantt and going to Kratus Bartok has made great advances in his research with the Geth.