Tahngarth, Talruum Hero

The whole design tension lives in one word repeated twice: power. The activated ability is a repeatable fight, and because Tahngarth deals damage equal to his own power while taking damage equal to the target's, it is only safe against creatures smaller than him and only profitable against ones he can kill without dying in the exchange. Pumping him raises the damage he deals without changing the damage he takes back, so the larger he gets the more lopsided each exchange becomes; the limit comes from the target side, where any creature with power four or higher trades blows that can drop him. That self-correcting math is what keeps a two-mana repeatable fight engine from running away with games. Vigilance reads like the enabler but cuts the other way: the fight costs and a tap, so activating it still locks him out of blocking on the crackback turn. Vigilance only buys a swing that leaves the fight option open afterward, not a way to fight and block in the same turn. The activated fight predates the modern fight keyword by more than a decade, doing the same simultaneous combat-resolution work that "fight" would later compress into a single word, but binding it to a creature who has to survive each exchange to use it again. His place in the canon is less about the card and more about the man: a minotaur of the Weatherlight crew, a recurring face across the saga's printings rather than a design that ever bent a format around itself.