Tooth and Nail for Ula & Kozi! When you absolutely, positively got to kill every motherfucker in the room, accept no substitutes.

Yes Forkbeard, I totally missed that one. Added to the list!

this will draw so much hate from your playgroup XD

maybe Elvish Piper for more cheat in options

Proteus Staff is a given; swap an Eldrazi Spawn for a possibility at cheating Ulamog, the Infinite Gyre into play for free? Yes, please!

Combos well with Scroll Rack or Soothsaying, also, to guarantee what you'll get.

I would recommend putting in more land ramping effects. While Mana Echoes with scion tokens is cute, I wouldn't rely on it as your main source for playing top end creatures. You could also look into cards like Fist of Suns to help reduce casting costs.

I'm excited by all these suggestions!

Of course, the Elvish Piper! Thanks PepsiAddicted.

Thanks ROMzombie, Proteus Staff seems to fit right in, but I'm concerned about the randomness of it. Kozilek, Artisan of Kozilek and both Ulamogs all have powerful triggers based on being cast and I'd hate to waste them.

Oooh, Fist of Suns is a great idea, enpc! Otherwise, I've got Urza's Incubator and Eldrazi Temple to reduce mana cost as well as a pile of other acceleration: Burgeoning, Growth Spasm, Chromatic Lantern, Darksteel Ingot, Dreamstone Hedron, Sol Ring and Thran Dynamo.

Instantly reconsidering the Elvish Piper in the interest of keeping a strict tribal theme. Though Pawn of Ulamog isn't technically an Eldrazi type, it's still on theme and generates Eldrazi.

Not to mention most of the big eldrazi are "on cast". Just run more ramp to make up for it.

I absolutely LOVE this deck! I've been trying to put together something along these lines but everything I did was a bust. Good going! Just an idea: some playgroups allow sideboards now (mine just started). Spawnsire is sitting here just begging to bring in those other cards, so might as well help the big guy out. Rather than more Eldrazi, I'm thinking of maybe just packing 15 copies of Eldrazi Conscription. A pack of spawn/scion hulking out just makes me giggle. :)

(Should add if it's acceptable -- my playgroup would kill me for trying it, which would be part of the fun). lol

Tengu316: Even with sideboards allowed, you can't have duplicate cards. This also includes having a particular card in both main and sideboard. That's the biggest problem with Spawnsire of Ulamog in commander, you usually already have the best eldrazi in your deck.

Thanks Tengu316, including a sideboard's a great idea! I agree with enpc though, I wouldn't want my sideboard to break the singleton rule of Commander. Therefore, I'll aim to include all the ooooother Eldrazi cards that didn't make it into the main deck.

I would maybe cut Broodwarden for something else. It looks like you have a mix of Spawns and Scions and it only effects Spawns.

Good call Ruffigan, Broodwarden made more sense in earlier drafts of this deck when I had a stronger token theme, heavy in the old Spawn. Replaced with the fun new Endless One.

This deck is begging to be targeted by a Bribery XD But other than that, I like the idea. +1

Hah, that's a good point TheBoraxKid. I suppose Homeward Path is my only defence against that.

i made a budget version of this deck and reduced the cost of it, for about half. It still functions properly, and brings out the big Eldrazi.

http://tappedout.net/mtg-decks/the-ceaseless-eldrazi-horde-budget/

I have of course, given credit for the original deck.

oh right, also consider adding Crystal Quarry !In combination with Mirari's Wake and Fist of Suns you can easily bring out Progenitus with Mirari's Wake and activate Fist of Suns with something like Sol ring and 3 lands.Also consider adding in Maelstrom Nexus if you want to all the way with 5 color combinations.

Polymorph would be hysterical. Zap a 0/1, reveal an Eldrazi.

Rakdos, Lord of Riots wouldn't be a bad card to throw in. Hit someone for a ton of damage, throw him out, and then you can play some of your colorless eldrazi for free, and the colored ones for only one or two mana.

Good tips Holmborn! I've tossed in a Crystal Quarry to partner with the Fist of Suns. I was kind of on the fence about Maelstrom Nexus, thinking maybe it was just a "good stuff" 5-colour thing. Then I woke up to the potential fun and added it to the mix.

Man, picturing a Polymorph in this deck is pretty funny, but the randomness worries me. I'd hate to accidentally waste a powerful "on cast" trigger with it. Still, not a bad idea Quicksilver.

I'll keep Rakdos, Lord of Riots in the back of my mind azure1659, but for now I feel like he's too conditional. Too many steps before he's of real value and I suspect my opponents will shut down him or the Eldrazi before he really delivers.

Well, if not Rakdos, Lord of Riots, maybe Mayael the Anima. You do have to invest a bit of mana into her, but it does cheat in a potentially massive creature that can't be countered, due to it not being cast, and play something a bit crazy, even in earlier sections of the game.

Door to Nothingness is a fun option you could try. It can steal games away from players who have absurdly high life gain decks, or decks that is hard to attack against.It's also some fun flavor as its a door to the blind eternities perhaps, home to the eldrazi.

what about Show and Tell and Sneak Attack to cheat them into play or Quicksilver Amulet

what about more draw power with the amount of mana you can get Blue Sun's Zenith would be good and Rhystic Study is good along with cards like Ponder and Fact or Fiction