Yako Tenma

Yako Tenma is the main antagonist of Yu-Gi-Oh! R. He is the protégé and adopted son (often mistaken, or mistranslated as younger brother) of Pegasus, and the biological twin brother of Gekko Tenma, who wants revenge for Pegasus' death and disappearance, although unbeknownst to him, it was actually Yami Bakura who killed him. He was always known as the less superior of the two Tenma brothers, constantly being defeated by Gekko. Yako appeared to have acquired an inferiority complex from his treatment by others. Pegasus however, seemed to be the only one who recognized he had potential, and that he'd develop into a great Duelist someday. He believes that Yugi killed Pegasus, and even when Gekko tells him that what Keith Howard told him is false, he said that "the reason Pegasus got killed is because Yugi won against him." Tenma's name comes from "Pegasus", which can be translated into Japanese as "Tenma", or 天馬.