Mal's through and through shot is perfectly aimed, and freezes his target effectively, letting Cullen get a clean strike in at the neck, taking off his head. He was probably already dead. Certainly fatally wounded. It's just insurance. Ounce of prevention and pound of cure, sort of. More or less. It also avoids the possible death cry.

Which Asher makes a non-issue only moments later. Well, at least that's all four taken care of. The one herded to the water with Jayne, the one run through and decapitated, the one smashed into the water with a boulder (which, he must admit, looks really freaking cool) and Bronson, and finally Asher's spinning top of death. If they're lucky, the noise won't have carried inside the cave.

He waits for a bit of stillness to return before looking to the three figures still standing. "Everyone unharmed?" Then he glances to Asher. Maybe the wrong wording. "Able to continue?" Better.