bonus points from me for Sengir Autocrat .

Well, since EDH is basically a battle of resources and attrition, I'd stock up some more value cards. Cards that advance your board and give you some additional advantage. Like Deadwood Treefolk , which happens to combine pretty well with cards like Gleancrawler , or a Eternal Witness /Hag Hedge-Mage type of card. In addition, I noticed that tutors are extremely good in EDH. So stock up on those. Play cards like Night Dealings and revel in just how great that card is in EDH, especially if you happen to play it with the Beacon of Unrest . Also, you may want to play some cards that disrupt your opponents in other ways than creatures. It never hurted me to be playing some discard, even if it is a lowly Thrull Surgeon

Anyway, that's just general advice, more specific advice would be to add more targets for the bloodspeaker, like Xathrid Demon , or Kuro, Pitlord (which is great if you have 40 life to spend), or card:Kyoki, Sanity's Eclipse if you add some more spirits/arcane. And of course Nameless Inversion and other changelings in your colors. Otherwise, he's not worth the mana you're paying for him, and you might as well swap him out for a Diabolic Tutor .

I'd also cut the the Darkest Hour , because it is pretty bad with all the nonblack removal you're running. You're always going to better off to cut it for the must have EDH cards like a card:Nevinyrral's Disk. And with all those sweet lands you're playing, you may want to consider playing non-basic land search(Reap and Sow ...and cut one forest for Yavimaya Hollow . Other than that, it looks pretty fun to play...There's not too many cards in it that get outclassed in the long game either.

Looking good looking good...

Darkest Hour is there because I sometimes found myself with an Ant Queen or Mycoloth producing large amounts of tokens...but they are green. They do not trigger Savra's Grave Pact ability, which is the theme of the deck and which eliminates all of everyone's creatures. If the time is right, I play it. If one of my removal engines is online and Darkest Hour would disrupt it, I wait until it's a better time because the Savra engine is the best removal of all - especially for Eldrazi and Indestructible creatures.

Last night while playing this deck I found a wonderful little combo - Doomgape on the board, and I sacrifice Lord of Extinction to gain 20 or so life, then also during the upkeep use card:Volrath's Stronghold to put the Lord of Extinction back on top of my library, then draw it and play it again. Each turn I gain life equal to the number of cards in all graveyards (which is a lot), while also using Savra's Gravepact ability (for free since the creature is green AND black). It was pretty nice until someone cast Nicol Bolas, Planeswalker , took Lord of Extinction and everyone ganged up on me. It was a lot of fun though. I did notice that the deck cannot destroy lands, except with Ghost Quarter . I think I should put more LD in here because Maze of Ith and The Tabernacle at Pendrell Vale were causing me attacking problems.

I will also add Yavimaya Hollow . What a great card.

Well, Reap and Sow should be a good place to start. I wouldn't go for dedicated land destruction, so you could play Acidic Slime as well, or Desert Twister , because EDH IS slow enough for that card to be good.

Good call. Yeah Desert Twister is a great card!!