Sometimes the best way to tune a deck for Modern and is to take it and mash it up with another popular deck. In this case, Eldrazi meets G/B Midrange. This deck has many Jund-like elements but also features some of the busted elements of the Eldrazi deck, such as turn 2 Thought-Knot Seer.
You want to control the early game with discard and removal spells, although that's typically only when you don't have a fast Eldrazi draw. If you're looking for something to bridge the gap, Ancient Stirrings can provide that. Either you'll find a giant creature or the mana necessary to cast one. Tarmogoyf plays a similar role of being something to do with your mana until you get to cast your big stuff. It holds the fort quite well.
The endgame is the aptly-named Endbringer. It's been popping up in some Eldrazi lists as a means of going over the top of the colorless version. Four may seem like a lot because of the six-casting-cost price tag, but most of the time it will feel like a four-mana card. Each ability is great and you'll likely end up with multiple activations per turn in the late game. It won't be long until it completely takes over.
This feels like an Eldrazi deck that isn't quite as fast but has disruption to slow down its opponents. It should be good against the Colorless Eldrazi decks but will likely struggle against U/R (and G/R) Eldrazi. Still, if you want a deck that won't mulligan as much and has a little more control over its own destiny, you could do worse than playing this deck.