I am surprised by how much bounce the cube supports and have continued to add in bounce but still don't feel there is room for all three of this, Boomerang and Rift
Its worth noting that your big Eldrazi have annihilator X, so once they start attacking, your opponents forces will crumple, so that works for interaction and removal as well
Casting Cost: Card Type: Sorcery Card Text: Draw cards equal to the number of cards in your library, then put a card from your hand on top of your library
Ayara, First of Locthwain Ayara, First of Locthwain taps to draw a card in a black deck with lots of creatures
Seven mana isnt something you can just put in your average deck and expect to happen though, but if your deck is slow or has some acceleration, Coliseum Behemoth should be fine to play
Assassin's Trophy Assassin's Trophy is some great instant-speed permanent removal that sees play in just about every BGx Commander deck