HI HELLO CAS. nnnnnope, no mortal soul, so he can't sense it. Grace is way not soul-y for Nico's purposes. Which is a shame because the faces Castiel would make... and the idea that there's a god out there who actually lets people escape death. God may be a dick but he's nicer than Hades.

Actually, do angels go to Hell when they die? 'cause then Nico would get a little feedback. I never got how Grace worked...