Hero of Leina Tower

Most heroic creatures bake their reward into the spell that targets them: a fixed counter, a temporary buff, a static trigger that fires the same way every time. This one instead converts targeting into an open-ended mana sink. Each spell aimed at it is a chance to dump leftover mana into permanent growth, scaling the payoff to whatever you can spare rather than to the protection spell's own ceiling. That structure changes how the card plays out across a game's mana curve. Early, the trigger is a modest tax you pay alongside a pump or a hexproof effect; late, with lands to burn, a single cheap targeting spell can balloon a one-power body into a real clock in one motion. The payment is the discipline holding the design in check: the counters are not free riders on every targeting spell, they cost real resources, so the creature rewards a deck with both a steady stream of cheap spells to trigger it and the mana flood to feed it. It asks two things at once (spells that target, and surplus mana to convert), and the friction of wanting both is what keeps a one-mana 1/1 from running away unsupervised. The growth is permanent and stacks, which is the quiet danger: protect it through a couple of turns and the investment compounds rather than resets.