From Warhammer 40k - Lexicanum
Vastael became the Voted-Lieutenant of the Dark Angels Legion's Firewing following the ending of the Ruinstorm during the Horus Heresy.
Before that, he had served in the Devastators of the Third Order, where he benefited from the mentorship of the Dreadwing's commander Farith Redloss. Due to this, Vastael originally swayed between joining the Dreadwing or Firewing, before finally deciding on the latter.
- 1: Dreadwing (Novella), Chapter 2