Still have a few more to go through, but...
Nemesis and Revival (DJ Skee & THX Remix Sample Edit) use the same choral riffs, which leads me to believe they (Revival's base track included) share some melodies. If that's the case, I have a feeling both may involve the Didact. I have to be honest when I say I could really see Didact as more of an ally or even a rival than an outright evil enemy though.
EDIT: Solace is giving me chills, reminds me of some of the oriental pieces in the Halo Legends OST. The chromatic percussion alone beats anything similar Marty's done out of the water. I really want to know the context, though, sounds absolutely horrifying if it was used in the proper scene.
EDIT 2: Gooooood fucking lord, Immaterial better be the background music for when we fight Promethean Chozo Ghosts using the Binary Rifle.
EDIT 3: Oh hey, 117 is Davidge channeling the good parts of Mike Jablonsky. It's the trailer music for the Movie Theater Trailer by the way. Sounds wonderful.