Spiteflame Witch

A repeatable life-loss engine on a two-mana body, and the symmetry is what pays for it: the activated ability bleeds every player at the table, controller included, which is why a recurring drain like this could be stapled to a creature this cheap. That symmetry only swings in your favor when you are already ahead in the race, or against opponents with no lifegain to flip the math back. The casting cost takes a single pip, so a mono-black or mono-red deck can play the 2/1 on curve, but the activation demands one mana of each color the moment you want the engine running, so any deck that actually wants the drain has to commit to both colors anyway. The body earns its keep across the whole curve: early, a 2/1 pressures in combat while the activation is still too expensive to lean on; late, once attacks stop connecting and lands pile up, it converts dead mana into damage. This is built for a low, aggressive shell that needs its flooded draws to still close games, with the all-in life cost as the price of putting recurring reach on a creature this small.