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