Just wondering that when Greymoor drops will my current vampire remain a lvl 10 with skill points refunded or will it force me back to lvl1 and i've got to lvl up again to 10?
Pretty much what @Vevvev said. You won't be sent back to level one, but it will be a little bit like you need to finish leveling it because there will be three skills with no XP in them. Also, you'll need a few more skill points from somewhere if you want to completely fill it out.
"He who fights with monsters should look to it that he himself does not become a monster...when you gaze long into the abyss the abyss also gazes into you..."