Oblivion Strike
Unconditional creature exile is one of black's oldest taboos, the line the color was historically not allowed to cross: black got destruction, edicts, and minus-toughness, but exile was the province of white. The devoid keyword is what licenses the break here. By stripping the spell of its color while leaving it castable for black mana, the card sidesteps the color-pie objection: this reads as a colorless Eldrazi-flavored answer that happens to live in black's hands, an effect that exiles cleanly rather than killing, even as its color identity stays black because of the in the cost. The price reflects that permission slip. Four mana at sorcery speed for unconditional exile is a deliberately soft rate, well behind what white pays for comparable effects, because the design is renting power from outside the color rather than expanding what black is owed. What you get for the premium is reliability against everything black usually struggles with: indestructible threats, recursion engines, anything that laughs at destruction. The exile clause leaves no body, no death trigger, no graveyard to mine later. It is a blunt, expensive, format-agnostic out, built less to be efficient than to hand black a tool it is not supposed to have, on a one-off Eldrazi pretext rather than a permanent rewrite of what the color is owed.

