Yeah, that's why I thought he would be in 4. But I definitely have a whole new respect on him. I'm not liking that all the main characters in the books are turning into villains. First the Didact then we find out who Spark was.
Yeah, it kinda sucks. And there's ample evidence that the Precursors were dicks and left the Flood as revenge on the Forerunners. It's like all of the old people suck, besides the Librarian, and she's kind of just ehhhh.