Here is the full list of all 23 Space Hulk: Deathwing achievements.
Kill 10,000 enemies
Complete Devotion branch
Find all the relics
Complete Commandement branch
Make 1111 assists
Complete Psy branch
Learn Vortex of Doom
Kill 666 enemies
Learn Inferno
unlock all Tactical Terminator's capacities in multiplayer
unlock all Librarian's capacities in multiplayer
unlock all Assault Terminator's capacities in multiplayer
unlock all Heavy weapon support's capacities in multiplayer
unlock all Apothecary's capacities in multiplayer
Finish a chapter without using a Psygate
Destroy a door
Hack a door
Use the Psygate
Kill a Broodlord
Kill a Genestealer's assault strain
Kill a Genestealer's stalker strain
Kill a Genestealer's warrior strain
Kill an hybrid psyker