In my opinion, Ulysses is the most memorable character in the entire game. Yet I feel that he should have been the game's main antagonist. For starters, it's because of him why we were in the position of carrying the platinum chip until we are ambushed by Benny and the Great Khans, and we all know how that went. He also scouted Hoover Dam for the Legion, trained the White Legs, and played a major unseen role in Old World Blues, responsible for helping Christine out. He is referenced throughout all the DLC's and near the beginning of the game by Johnson Nash, but it isn't until the end of the last DLC Lonesome Road where you finally come face to face with him. He is a major driving force of the story and would be a much more fitting antagonist of the game than either the Legate, General Oliver, or Mr. House. At least that's my opinion.