Frozen Blood
Nero used FAK to stop any of Jackals bleeding, but that was far from healing him. Ideally, he should not be doing anything at all, but the situation didn't allow for that. The other soldiers were hurt as well, and though Nero helped remove the Mutt corpse from atop them, even in their injured state they were wary of him. After all, they had no idea why he killed Herbert.
But as long as they stayed in a corner and didn't bother him, Nero didn't mind leaving them be. He rushed back to the door.
The berserker's kick had cleared some of the corpses in the way, but it had also scared away the living Mutts from this area so they got a brief respite. But a single glance in the now bloody room revealed that their despite would only remain brief.
There were still countless Mutts flying around, though they were less focused on fighting now, and more focused on avoiding the berserker.