A passably fun story about Corax and Lorgar being badass at one another. Raises and does not answer questions about how Corax could be in this form of vengeance revenant within the warp for 10k years without running out of rank and file Chaos Marines to merk. It seems like the only thing that could stop him (barely) was Lorgar (along with Marines running support). I guess you can say "the Warp fucks with time" but I mean, they can't reliably reproduce new Marines and he rips through the ones present in this story in no time.
The depiction of the Chaos slaves was interesting, so minor shoutout to that.