Spoiler: RaxYou don't think it's pure regeneration, but fast healing instead. Two of the weapons look like they're masterwork and the other, the dagger, is alchemical silver.
Spoiler: SmineranoYou think it has something to do with his mutation.
Spoiler: RaxThe entry east immediately curves downward in a flight of stairs. However, attempting to head downward is futile, as a cave-in is in the way.