Dwarven Armory

The whole engine runs through a window the modern game has all but forgotten: the upkeep step. That timing restriction is the entire design. It forbids the combat trick, forbids the end-of-turn surprise, and schedules the conversion of land into power onto a clock the whole table can watch tick. The clause is not as toothless as it reads, though; activated on your own upkeep, the counter lands before combat, so the buffed creature swings that same turn, and on an opponent's upkeep the growth is there to block immediately. The real friction is the cost: you dismantle your own mana base one land at a time to grow a creature. The +2/+2 counter is a permanent modification (it survives the creature changing hands or the game grinding long), but the creature carrying it is not, so any removal spell erases every land you fed into it. The card also targets any creature, an opponent's included, which Ice Age-vintage design occasionally treated as a feature rather than a bug. The underlying instinct, turning surplus lands into board presence, is one Wizards has revisited many times since with cleaner execution, but few later versions kept the deliberate upkeep-only clock that dictates exactly how and when this can ever matter.