The Knight Atrapos is built from the loping Cerastus pattern chassis and stands a good deal taller than the Knights Magaera that share in the favour of Mars. As the Horus Heresy erupted they often duelled enemy Knights as their graviton singularity cannons and massive lascutters gave them a serious armour-piercing punch – reflected by the Macro-extinction Protocols special rule which gives them re-rolls when fighting other Super-heavies, Knights, and Titans.

They also sport a beefed-up defensive profile, with a stronger Ion Shield than a Cerastus Knight to keep them in the fight.