yeah I was kind of surprised by that myself. I've never heard of a vampire reincarnation seeing as how they are usually dead...so no soul to reincarnate. ....Unless our given impression was wrong and he wasn't a vampire which just leaves me with one question....why the sudden desire to suck your horses neck....hmm unless he was like the father and perhaps still had a bit of human left in him before he fully became vamp or something so part of his soul reincarnated. hmm well I guess it could be possible.
he's not a vamp, so reincarnation is possible..
and he's about to suck the horse's blood.. maybe because he wanted to try to become one.. but dean refuses to make him a vampire.. that's the feeling i'm getting..
Rencarnation? Eh.. (=・ω・=)