Warhammer 40,000: Rogue Trader

Got this first try. With any Warrior, ideally tanky, you can use Taunting Scream to keep Boss- Aurora (Chaos Marine) focused on them as you quickly eliminate the 6 or so weaker mobs then focus all on him. Abelard is great for this role and he should be your main tank anyway at this point, Heinrix can do this as well. Also with Cassia, you can use Notch of Purpose to pull Aurora closer to your party near the point where you entered. Using these you should be able to keep him off any shuttle as game will priotize hurting your party over the shuttles. It helped having Pasqal, Idira, and Cassia debuffing, as my Psyker main character and Argenta did their damage.