Doran, the Siege Tower

A 0/5 that hits like a wrecking ball, because the entire deckbuilding proposition of this Treefolk hinges on flipping the axis combat math runs on. Power stops mattering; toughness becomes everything, and a board of fat, defensively-statted creatures suddenly attacks for numbers their printed power would never allow. It turns walls into beaters and rewards a creature suite few build-arounds ask for, where high toughness at a low cost is the single constraint that matters. The static effect is symmetrical, and that is where it gets interesting: opponents' creatures also assign damage by toughness, so trades and blocks that looked safe stop behaving the way the board state suggests. That two-way nature is the discipline keeping it honest. This is a continuous effect that rewrites a fundamental combat rule for everyone at the table, not just its controller, so the player who built around it has to read the new math more carefully than anyone. The supporting color identity is no accident: white and green field the cheap, sturdy bodies the ability wants, and tribes like Treefolk and Walls are stocked with creatures whose toughness dwarfs their power (Wall of Roots, Tree of Redemption, Indomitable Ancients). Long a Rock-style midrange centerpiece in eternal formats before it became a Commander fixture, it sits in a small, strange category of static lords: the payoff is not a number on the card but a change to the language combat is conducted in.