The Eldrazi menace has been unleashed in Modern, and it's making waves. Not only are the colorless and U/R versions tearing it up, but there is still room to explore in the archetype.
This version goes a little bigger than the other versions, sporting both World Breaker and Kozilek's Return. In a world where people may try to beat you with Ensnaring Bridge and Ghostly Prison, World Breaker is a fantastic card to have access to. Additionally, I don't think the pseudo-mirrors can beat the back side of Kozilek's Return.
You lose out on the creature-lands like Mutavault and Blinkmoth Nexus, but you make up for it with castable spells. If you wanted to, you could even splice some of the technology from the colorless version into this deck. Simian Spirit Guide and Chalice of the Void could make excellent additions.
Grove of the Burnwillows is a fantastic reason to be aligned with G/R. It's effectively a tri-land for the archetype with minimal downside.
The sideboard has some nice options, such as Lightning Bolt and Nature's Claim, which the other versions don't have access to. Ancient Grudge is another big player that can swing the Affinity matchup.