Forcemage Advocate

The whole design rests on a wager: that the card you hand back to an opponent costs them more to recast than the +1/+1 counter cost you to deal out. One tap returns a card from an opponent's graveyard to their hand and grows any creature you choose, and the line only profits you when the recursion you grant is a net loss for its owner. The asymmetry in targeting is what makes the activation worth threading: the graveyard pull is locked to an opponent, but the counter is not, so the same tap that hands a card back can also pad your own attacker. The gift, of course, is genuine. A card returned to hand is a card the opponent can cast, so the math only works when you are denying a graveyard mechanic that needs the card in the yard (delve fuel, reanimation fodder, escape kindling, threshold count) rather than something they were happy to recast anyway. Done right, you are not removing a payoff so much as taxing it, forcing mana to re-buy what they had already paid for once. The 2/1 body is fragile, but the ability carries no sacrifice clause, so as long as the Centaur survives to untap you keep levying that tax turn after turn. It belongs to a school of design where the drawback is meant to be someone else's problem: the upside is free, bolted to a downside you accept only because you have built a deck that punishes the gift faster than its recipient can spend it.