A former Behemoth security regular joins Ashford, dons stolen recon armor, and reaches Bull's elevator hiding place only to receive two live spine-cracker grenades.
Casimir once rotated ordinary Behemoth security duty with Serge, Corin, and Jojo during the blackout recovery, suppressing panic and rescuing trapped crew. In the later command split he chooses the Ashford Loyalists and becomes one of four people selected for confiscated Martian recon armor.
The suit's power helps Casimir's group overwhelm engineering despite their lack of training and ammunition. They tear through workstations, improvise firearms by breaking trigger guards, cut the defenders off from the drum, and pursue survivors into the external elevator shaft. One visor is cracked by Juarez, but the group reaches the blocked elevator after Bull sends the others onward.
Casimir's armored head appears through the cut floor hatch. With no return fire, he rises far enough for the cowling to turn transparent. Bull recognizes him and grins at the personal coincidence. Casimir then sees two spine-cracker grenades floating toward him on minimum fuse, a final encounter between former members of the same security organization now committed to opposite captains.
Casimir is an adult man whose natural features are not described. He is enclosed in massive black-and-red Martian powered armor with an opaque cowling that can turn transparent.
Casimir is the armored loyalist who carries Ashford's counterattack to Bull's last position and becomes the target of the security chief's final trap.