It That Heralds the End

Two mana buys two jobs here, and both point at the same deck. The colorless in the cost is the honest tax: this only slots into a manabase built to produce it, so the reduction on seven-plus-mana colorless spells is a reward you have already paid for at the mana source. That discount is the load-bearing half. Eldrazi decks live and die on getting to the top of the curve a turn early, and shaving a mana off the true monsters (the ones that cost seven, eight, or more) compresses the gap between ramp and payoff more than a single mana usually should, because at that price point a turn is often the difference between casting and not casting at all. The +1/+1 anthem for other colorless creatures is the second job, and it quietly recasts this from a pure enabler into a body that makes the swarm of Eldrazi Scions, drones, and processors around it hit for real. The design tension is that neither ability is redundant with the other: the cost reduction serves the top end, the anthem serves the bottom, and a colorless-matters shell wants both halves at once. It is a two-drop that scales in two directions from the middle of the curve, which is a rare thing to ask of a card this cheap.