You are running 11 cards too many, really you want to focus down on your wincon.

Sadly Bond/Blood combo is also too slow for Modern, but if you are looking for casual it is fine.

You might want to look at Rhox Faithmender, Beacon of Immortality, and Boon Reflection to gain even more life. Erebos, God of the Dead will stop your opponents from gaining life and you can use it to draw cards if you need to. Exsanguinate, Leechridden Swamp, Polluted Bonds, and Blood Tribute would help with dealing damage and gaining life from everyone. painful quandry and Temporal Extortion give your opponent the ability to choose between damage or something that will benefit you and can cause them to have to make some difficult choices. Underworld Dreams functions similar to Fate Unraveler is a nice source of damage every time they draw. It punishes people for drawing several cards while being cheaper to play and not being affected by most common board wipes. I would personally replace Corrupted Roots with Contaminated Ground because it can hit more lands. Serra Avatar could become pretty big in your deck as long as you can keep your life up. if you want another card similar to Felidar Sovereign, look at Test of Endurance. You need 50 instead of 40 but it could possibly be another win con for you.

I forgot to add, if you want to gain life whenever a creature enters you could add Soul's Attendant and Soul Warden. They would help trigger your combo or at least cause you to gain a little life throughout the game.

adding to what bomley20 already said:

1. You could try out some more of the cards with "Extort" (especially Thrull Parasite since he doesn't only come early and bring Extort with him but he also gives a way of handling Planeswalkers!)

2. Instead of Wall of Essence (or in addition to it) you could play Wall of Hope and/or Souls of the Faultless

3. Angel's Mercy, Dash Hopes and Taste of Blood are pretty bad and you should probably exchange them for some of the cards we have suggested

Cliffhaven Vampire from oath of the gatewatch would fit well in your deck and could be a back up for your Sanguine Bond in the Exquisite Blood + Sanguine Bond combo. It would hit the entire table but only deals 1 instead of equal to how much life you gained.

Pillory of the sleepless would fit right in.

Since you have 2 soul sisters, you might want to look at Suture Priest as another way to start your combo. Karlov of the Ghost Council will become a pretty big threat with all of your life gain and will give you a decent amount of removal. Ayli, Eternal Pilgrim could also provide a decent amount of life and removal for you.