In Warhammer 40K the Deathwatch is a group made up of all the other Space Marine chapters. When a marine joins they paint their armor black to match their new brothers. This is a great group to use for games because it lets people pick characters from their favorite Space Marine Chapters and doesn't just focus on one like the underrated Ultramarine game did
The game will contain 38 different Space Marines with over 150 different weapons and wargear. Once you put your team together you'll take them through 40 different missions. Of course the game will support in app purchases. The ones in Warhammer Quest were for things like new areas, new enemy types, new heroes, and new weapons. I'd expect Deathwatch to have a very similar setup.