Kreia actually had a point. I have no idea what he was going with Ulysses. His writing's all over the place. A frumentarius, but he doesn't see Caesar handling his tribe like he did every other tribe coming. Fancy view of people as agents of concepts yet doesn't see any in himself. Hates you for the unintentional consequences of your actions that supposedly happened while ignoring his own.
The other DLCs hype him up, and the payoff is...eh. His personal connection with you is easily the worst bit of writing. If he were just some renegade member of the Legion who decided to do his own thing, that would've been more interesting. Make all the mentions of a different courier have more weight. The guy could've been you, but he found his own Vegas or a way to make his own faction: one of the last stockpiles of nuclear weapons in America. He came to the west from the east and you went to the east from the west and other such poetic crap.