Katan is one of the Cherubim. He was originally a Grigori, but was given a body by Rosiel when he was still sane. He worked to achieve the rank of Cherubim solely so that he could see Rosiel again. In a sense he is Rosiel's son, and he loves Rosiel deeply. He resurrected Rosiel in the hopes that he would take control of Heaven again and end the corrupt dictatorship. Unfortunately for Katan, this plan backfires, as Rosiel only cares about having Alexiel love him and tell him that he is beautiful. Unlike Kirie, Katan disapproves of many of Rosiel's actions, but he cannot bring himself to leave Rosiel's side.