I see what you're going for with this deck but your creatures and spells are a bit all over the place. My recommendation is to focus more on the ORZHOV SYNDICATE and the cards that came from the RETURN TO RAVNICA block. That would be a good start. Next decide are you trying to STEAL health without having to attack or are you trying to TAKE life through combat. This is the crucial part because this is what decides how your deck plays out every time you use it. Also you might want to try and shape up your mana base a bit. I see some lands that have strict requirements just to be played and used. Try keeping the
isolated chapel and the basic lands. Switch the other lands for
scoured barrens and orzhov guildgates because you want to gain health and not waste your precious time fiddling with mana requirements. If you want the deck to be more creature based with the combat then try adding some creatures that wither cannot be blocked or have first strike and then give them
vigilance if you can help it. This way you get the most out of your creatures that have
lifelink. If you prefer the indirect method then you can play spells that drain health like
stab wound,
one thousand lashes,
purge the profane (because it gives you hand advantage) and
sinister possession. It's knowing how you want the deck to run that gives you the best handle on the cards you place in the deck.
To the deck itself i have these suggestions; 1. Don't play cards that destroy your cards in mass because with White/Black you're going for board presence and field control. Destroying your own stuff only sets you back. 2. If you're gonna play cards that give people draw power like
sign in blood (i recommend targeting the enemy), then play
mind rot and cards that you can use to rip cards from their hands that you just gave them. 3. Sideboard the sublime angel and
divinity of pride. Divinity only works once you have your health maxed out and the angel basically says ' you can only attack with one creature if you want it to get stronger' which can
hinder your deck if you're not playing tokens or lots of creatures with exalted or defender. 4. you only have 20 lands in a 60 card deck. usually I would recommend a minimum of 24 lands to keep from running into mana droughts. If you use more basic lands then you can run your deck faster because your lands enter untapped. Let me know about your thoughts later.