Arboreal Alliance

Elves and Treefolk descend from green's earliest creature-type work, but they were built to pull in opposite directions: Elves swarm and attack, Treefolk root down and grow enormous. This staples them together and asks the aggressive half to feed the patient half. The entering token scales with whatever mana you sank into X, and every subsequent Elf attack populates a copy of it. Because populate duplicates a token exactly rather than enlarging one, the payoff is locked the moment the first Treefolk hits: an X/X copied into a widening line of X/X Treefolk, not a wall that swells each turn. The size is a snapshot, and the copies inherit it. Worth noting is where in combat the populate lands. The attack trigger resolves during the Declare Attackers step, so the copy does enter the battlefield mid-combat, but it enters not attacking, sitting behind your Elves rather than joining them. It changes nothing about the swing already declared: it does not tax the opponent's blocking math, and it does not add to the damage on the table this turn. The token is board development collected on the back of an attack that was going to happen anyway. It thickens your position turn after turn without touching the current combat. That is the honest read: a build-around that expects the Elves already online and treats the Treefolk as accumulated interest, a defensive dividend paid out every time the aggressive side does its job.