The cultist received Arkhah's bayonet charge directly in the chest, and responded by drawing a knife and rushing for Arkhah's throat, in a clumsy and easily dodged attack.  As good as the mutants were at surviving sharp things in their chests, they coudn't shoot straight or fight worth a damn.  The initial mutant drew a cartoonish shotgun pistol from his belt, and slowly backed behind Arkhah, getting ready to rush the Kroot.