nullifies regeneration

That wasn’t where I was paying attention to, though. My attention turned to the stump of his left arm, which was still bleeding, if much more sluggishly than it had at first. It was healing, I was pretty sure it was still healing at an accelerated rate, but it was healing much slower than it had been even a few moments before. I looked towards his right side, where I’d cut him less than a minute ago, and found it was still dribbling blood. It hadn’t healed up, either.

I felt a smile pull at my lips. I was right, then. Like this, he was a dragon, and so like this, he was more vulnerable to my sword than ever.