Abomination, Terrifying Titan

Power-up is a mechanic built on a single escalating investment, and this is its fight-oriented incarnation. The activation reads like a punishing seven-mana sink, but the parenthetical is where the design lives: fire it the turn he lands and the cost drops by his own mana cost, so the activation shrinks by the moment he enters. That reduction reframes the whole card. Instead of banking a full activation for some later turn, it rewards deploying him and following up immediately, turning a body that arrives for four into a threat that grows itself and picks a fight the same turn. Crucially, the ability is a fight, not an attack: he deals damage equal to his power to the target and takes damage back, all of it outside of combat, so no haste is required and no blocker gets in the way. The exchange is reciprocal, which is what keeps this from being clean removal. A large enough creature can absorb the fight and swing back into him, or survive it entirely, so the +1/+1 counter carries double weight: it pads his toughness for the brawl and leaves him bigger afterward. Trample means that extra size does not get chump-blocked into irrelevance when he does eventually attack. The once-per-ability restriction keeps the escalation honest, since you cannot loop the fight to grind through a board: the power-up is a discrete, permanent commitment, one counter and an optional contested fight, the kind of on-curve tempo swing red-green midrange is built to reach.