Barrage Tyrant

A 5/3 body is glass: it trades down to most things its size and dies to a stray burn spell. The activated ability is the whole reason to play it, and it rewires that fragility into a threat the board has to answer right now. Sacrifice another colorless creature and the Tyrant throws that creature's full power at any target, face included. The Eldrazi shell makes the colorless clause read as a non-restriction rather than a tax: in a deck built around devoid creatures and Eldrazi Scions, the fodder is already on the table, and the Scions you would otherwise tap for mana become single-shot artillery. The wrinkle worth dwelling on is timing. Because the ability has no sorcery clause, you can hold up the activation as an instant-speed combat blowout or as a removal spell on the opponent's end step, converting a creature you were going to lose anyway (a blocked attacker, a token about to be exiled) into reach the board never saw coming. It also stacks: with enough mana and bodies, the Tyrant becomes a repeatable damage cannon that breaks a stalled position no other card on the table can. The activation cost keeps it honest, though. Three mana and a creature per shot is real friction, so the card asks for a board you have already committed to spending rather than rewarding you for nothing.