One of the many problems with Nathan's death is the show forgot its deus ex machine...Claire's blood could have healed him.
That was the saving grace - hopefully the writers have now realized what a bs cheap out that is, and will forget they ever thought of it.
Well in the great Heroes tradition of editing out totally vital information, they had a line in the script that explained the healing blood only works once for a person.
Thank GOD they edited that out.

Inventing a bs cheap out is bad enough, but inventing arbitrary bs rules for the cheap out would make things worse. A line that that would be a throw-a-shoe-at-the-TV moment. Like this show has so few of those, huh?
Or are they saying that since he was restored by Adam's blood that Claire's blood wouldn't affect him?
Yeesh. A line that that would be a throw-a-couch-at-the-TV moment.