Academy Rector could help get the enchantments Exquisite Blood + Sanguine Bond

Nice list! Love the Tainted Sigil inclusion :) I've got an Ayli list too if you wanted to check it, though mine's more token focused - http://tappedout.net/mtg-decks/aylis-army-of-unlife/

Oh also, for what it's worth, Sorin + Exquisite Blood doesn't net you 30 life, because Sorin's middle neg doesn't drain their life to 10, it just makes it become 10, so it doesn't trigger Exquisite Blood ._.

Mortphose: I think (http://magiccards.info/query?q=%21Sorin+Markov) the opponent will actually loose life because setting the life to 10 will be causing the player to loose the points (see also comp. rules 118.5).