I love it. I may borrow a good bit for my eldrazi deck.

I don't know if you are new to EDH but with Emrakul, the Promised End as your commander, the color identity of the deck is completely colorless. There can't be any colored mana symbols whatsoever. Kozilek EDH This is my Kozilek EDH deck, as you can see there aren't any colored cards. This also excludes the Devoid cards from the BFZ block.

For any future viewers, this is a CASUAL commander deck. You can't use colors in a deck with a colorless commander. However, when you have rly nice friends and are an eldrazi fanatic, you do it anyway.

The point of EDH is to have a Commander and a deck that supports it's colors. If you are just playing whatever you want, regardless of color identity, then it's not EDH, casual or not...I'm an Eldrazi fanatic as well, which is why I built my Kozilek deck. The fun of it is having to build around the identity of your commander and playing that balance... If your play group doesn't care then whatever but it's not EDH.

How's the mana base and ramp to you. I want to make a 4 color eldrazi deck and yours the best I've seen so far. I see that your using a 40 land mana base with scions for ramp with little mana rocks, would you say its faster in ramp than mana rocks. Also which do you think would be the best to keep outside of the game for coax from the blind eternities and spawnsire.

DragCov, Its so nice to see someone that has an appreciation for Eldrazi like I do, your comment made my day.

Alright to answer your questions (correct me if I didn't get the questions right, or didn't understand the question fully):

1. Is this deck faster by using ramp or mana rocks? Answer: The most efficient mana rocks that I see are ones that tap for colorless mana, and with too many creatures that cost color, that can actually sometimes be a downside in a 4 color deck. since you have such a wide-distribution of colors, ramp can sometimes be seen as more efficient than colorless mana rocks, as you are still sped up with mana, and get lands that you can tap for lands that you choose based on what you need, so sometimes its better to have a ramp spell than a mana rock. Since too much of each seems to end up as a downside in a 4 color deck (at least as far as I've seen), I like to try and find a balance of both, so I get good mana boosts without hindering efficiency. My favorite card that does both is Growth Spasm. 3 mana to cast, grab a basic land and put it down tapped, and put down a 0/1 Eldrazi Spawn to use as colorless ramp or a chump blocker.

2. What Eldrazi is best to keep outside the game for Coax of the Blind Eternities and Spawnsire of Ulamog?Answer: All of the Eldrazi you own. That's right. All of them. You can never have too many Eldrazi with you. Every Eldrazi is unique in its won way, and you want to use cards like Coax from the Blind Eternities to pick the one you want based on the situation you're in, and what you need. Your opponent has a ton of lands in exile? Grab a Oblivion Sower. Want to return a good instant/sorcery from your graveyard to your hand? Grab a Vexing Scuttler. Have a bunch of mana to spare and want a big creature? Grab an Endless One. I can go on for hours, but I'll stop there. Also, the more Eldrazi you have outside the game, the more you put down for free with Spawnsire of Ulamog. You can essentially bring the whole game to an end once it gets to be your turn again, by swinging with an hilarious amount of damage, and we aren't even counting all the effects each individual Eldrazi brings with them. Not to brag, but I have almsot every Eldrazi card ever printed (I'm just that devoted to Emrakul), and I carry around a separate box with all my extra Eldrazi whenever I play with this deck. The more the merrier man.

Any more questions? Ask away, I'm more than happy to help you with anything Eldrazi.

Thanks, yeah that makes sense to use any and all i own making the card a tool box. I kinda wish now there were at least 2 more spells that did the same thing. I was a little worried about the mana rock to ramp ratio because like you said a lot of the eldrazis are colorless while your spells are going to take advantage of the 4 colors.

DragCov There is Mastermind's Acquisition, which is a recent card. Its a Diabolic Tutor or a Coax (although better), your choice. Its another card you can snag Eldrazi with. I'm still looking to see if I can add it into this deck, its a really useful card.