Three Tree City

Tribal decks have always wanted a payoff that scales with the board, and they have usually gotten it stapled to a creature or a spell you had to protect. This puts the scaling on a land, which changes the math entirely. The type gets locked in as it enters, so the choice is a commitment rather than a moving target, and the second ability turns a wide board of one type into a burst of mana in whatever color you need. The elegance is in the split between the two abilities: the tap-for-colorless line keeps it functional the moment it comes down, so you are never sitting on a dead land while you assemble the tribe, and the two-mana activation only pays off once the board has grown. That gap between "produces one colorless" and "produces a fistful of any color" is the whole tension. It rewards a committed creature-type strategy without punishing the turns before that strategy arrives. Ramp effects tied to creature count have shown up before, but bolting one onto a legendary land with no color cost of its own is a quietly aggressive piece of design: it asks nothing of your mana base and gives back proportional to how hard you have leaned into a single type.