Zankoku had taken quite a few hits at this point. His weapon allowed for wide swings, but the vampires still managed to close the distance and deal damage. The covering fire from Nora was one of the main reasons that he was still alive.
Merlin began moving to assist Zankoku, but his eyes were drawn to the sight of Tiny. The large man was somehow holding back the largest group of vampires. And while he was taking hits, similar to Zankoku, any hits of his that connected effectively removed that particular vampire from the fight, either permanently or temporarily.
Merlin's eyes snapped back to Zankoku's situation, but he only just noticed that one of the vampires had broken away from Zankoku's range and chosen Nora as its target instead.