[quote=@Ever Faithful]
Hmmmm, would it also nullify magic healing?
[/quote]

Debatable, and I guess it's upto Wraith. The difference between the two is blood healing requires blood, something physical, going into the body whereas magical healing would just give the body energy to expediate the healing on its own. Though as I said its really down to Wraith as a player, since its affecting his character.