Voldaren Thrillseeker

The mechanic usually rewards keeping the creature that receives its counters: an evasion word or a passive buff you want to preserve. Here the donated text is a sacrifice ability, which inverts the whole premise. Point the two counters at another creature and it can, for one mana, throw itself at any target to deal its power as damage; keep them and the enterer becomes a 3/3 that does the same. Instead of a keyword you want to protect, this loads a one-shot burn spell onto a target you choose, then invites you to cash it in. The sacrifice clause is the counterweight that keeps the counters from being free tempo: the reach is real, but collecting it costs you the creature holding it, so every point of damage is a point of board you spend. That math favors a board already going wide and hunting the last few points of a race, and it works against a build that wants its bodies to stay put. It is a burn spell that arrives wearing a body, priced in creatures rather than mana.