Ulysses was originally going to be a companion, but was cut from the final version of the game and then put back in for the Lonesome Road DLC as the main antagonist.

This would have made him a Legion-sympathetic companion and would help explain Legion backstory elements, as there wasn't much Legion support from any of the other companions. He would have also reacted strongly to NCR/Legion conflict and the player's role in it, acting as a sounding board when possible.