Beleg

I prefer Ulamog over both Kozilek and It That Betrays. You aren't getting the cast effect when you use a trap, and Ulamog has protection from a few common removal cards (primarily Day). Also, I recommend testing it with 2 Garruk and 2 Omnath, Locus of Mana. I run a similar deck, and Omnath is fantastic, he gives you the option to hard cast your Eldrazi. I started with a 2/2 split, and I've found that Omnath is almost always more useful. Also, you might consider swapping the Llanowar for Explore to dig to your trap faster.