Yu Yevon

Yu Yevon is the overarching antagonist of Final Fantasy X. He was the leader of ancient Zanarkand, Lady Yunalesca's father and the creator of Sin. A mysterious entity, the only information given about Yu Yevon comes from Bahamut's fayth, Yunalesca, Maechen, and Grand Maester Mika. Yu Yevon's role is that of an impersonal antagonist; while Jecht and Seymour fill the roles of personal antagonists for Tidus and Yuna, Yu Yevon has no personal connection with any of the main cast.