Nianque

You're missing a vampire... Sorin. And you could use some hexmages also.

Skithiryx, the Blight Dragon with swords.

And what gave you that impression? There are 3 confirmed planeswalker loyalties to Nicol Bolas: Nicol Bolas, Sarkhan the Mad, and Tezzeret, Agent of Bolas.

The next planeswalker will most likely not be working for Bolas, but working for Phyrexia instead.

I just realized that Rhys is a bit more expensive than I thought... I might go with sound the call though.

I really like the concept, but it seems a little slow to me, even with the dark rituals. I would recommend more guul draz vampires or guul draz assassins.

Sorin is okay in this build but not the best. Try and get some captivating vampires, they are awesome for this kind of thing.

Rhys the Redeemed is worth looking into... how many should I put into my deck?

What's your counter to Haunting Echoes?

Haha... Oh wow, I love this idea!

I think you could use some more mana ramp. Realm of Discovery would work really well in this deck.

Why would you use terramorphic expanses if you're only running white? They work better for multi-colored decks.

I reccomend taking out Death's Shadow and using Guul Draz Vampires instead. That way you can play them on turn 1 without them dying and have more creatures to sac and get Demon of Death's Gate out.

What would you recommend though? Straight acceleration like Llanowar elves or bringing out forests with stuff like Sylvan Ranger?

This is very well put together... I commend you on making a working 5 color deck.

It's a shame that there are not enough rats to make one that's standard...

Oh... I hate this deck. I had a friend play infinite fireball and infinite splinter twin on me a few times. But his deck was a bit different and was R/W. He's since scrapped it for a Reaper King deck.

The ultimate counter to most rat deck killers... I like it!

Wow... That is a whole lot faster than any of the decks that I have.

This deck dies to flying... I would take out 4 land and add in Ezuri's Archers. Also I don't think you need 4 Ezuri's 2 would probably be enough, I would sub two of them for Nissa.