Ivan

Ivan (イワン Iwan?) is the strong man of the Bio-Hybrid trio consisting of himself, Kouki and Nanami. Ivan seems to have difficulty with holding his inner thoughs, and tends to blurt out what he's thinking without realizing it. After meeting her for the first time, he developed a sort of attraction towards Yoshino Fujieda (calling her his "honey bun" at one point). After gaining his ability to assume his final form, this prompted him to engage Rosemon in a duel for Yoshino's love, only for him to be defeated at their hands.
In the same episode this battle occured in, it was revealed that Ivan is something of a mercenary, and underwent his transformation into a Bio-Hybrid for the sake of money. It was learned that he also had many brothers and sisters in Russia, and that he was fighting for their sakes. In the last episode, Ivan was also rising his D.N.A. into the sky, together with his siblings.