From Warhammer 40k - Lexicanum
The Fleet Nihilus is a vast Imperial armada, that is led by Commander Dante, Regent and Warden of the Imperium Nihilus.
It uses the Blood Angels' Skyfall space dock, as a support base and is composed of warships that Dante has been able to summon to Baal, or that fled there. The Regent believes that the Fleet Nihilus can be the beginning of a reclamation force, that will restore the Imperium's rule to the domain placed in his charge.
- 1: Codex Supplement: Blood Angels (9th Edition), pg. 22 - Commander Dante