World Shaper

The trick here is that the two abilities are designed to be self-feeding. Attacking mills three cards, which loads the graveyard with lands; then the body dies and dumps every one of those lands onto the battlefield tapped. The first ability is the fuel, the second is the payoff, and a single creature carries both halves of the loop. Older self-mill ramp usually needed a separate engine to convert a stocked graveyard into board state; this design folds fuel and payoff into one 3/3. The tapped clause is the cost that keeps the payoff from being free: the returned lands arrive asleep, so even when you cash in on your own turn, the mana explosion is delayed a turn rather than immediate. The dies trigger also reframes how you want to use the body. A 3/3 that wants to attack and a 3/3 that wants to die pull in opposite directions, and this card asks for both: swing to fill the yard, then feed it to a sacrifice outlet or throw it in front of a blocker to collect. It rewards a deck willing to spend its own creature, which is a less common ask than ramp normally makes. The land mass it returns scales with how long you have been milling, so the same card can return two lands in a curve-out or six in a grinding game, and the upside is entirely a function of how patiently the graveyard was built.