In a setting as self-consciously dark as Warhammer 40,000 you really have to go out of your way to seem like "a bit much", but the black-clad killers of the Officio Assassinorum pull it off. They look like something a teenager who read too many Wolverine comics would come up with, and I love them. After going under-represented in 40K videogames they'll be joining the ranks of Chaos Gate – Daemonhunters in the Execution Force expansion.
A previous teaser video made the fact the assassins were coming pretty obvious, but who bothers with subtlety when you've got power claws and skull masks? Your squad of Grey Knights will be able to recruit four assassins, one from each of the four temples: Callidus, Vindicare, Culexus, and Eversor. Callidus are specialists in disguise and stealth, Vindicare are long-range snipers, Culexus are psychically null and therefore experts at shutting down psykers (and are also invisible to daemons), while Eversor are berserkers who just take lots of drugs and kill everyone.
Execution Force also adds two more mission types to Daemonhunters' campaign. Boarding Actions let you hop a squad over to an enemy cruiser to disable its power generators, while Tentarus Hive missions set you up against a new threat called the "Tentarus Bloom" across five maps.
Your existing troops also get a boost with some new weapons and armor for the Grey Knights as well. They need it. Daemonhuters was a tough campaign to get through the first time, though it's tempting to go back and see how I fare with a better understanding of how to put a squad together and manage the strategy layer. Oh, and also four well-equipped murderers and a dreadnought, courtesy of the previous Duty Eternal expansion.