Thread:OBWforumsVSthreads/@comment-34272082-20190115034422/@comment-34890725-20190115034647

Bill regenerates once Alduin physically hits him. Though, Alduin’s likely to eat him, meaning his essence (soul) is devoured too. Bill needs his soul or mind to regenerate, but that won’t be left there.

Needless to say, Alduin via void and soul hax.