Dawnhart Disciple

The reward here is a snowball priced for a curve that never stops adding bodies. Every additional Human that enters under your control pushes power and toughness up together, so in a deck built to spill two- and three-power Humans onto the board in a single turn, this can spike well past its printed 2/2 for one aggressive attack. The bonus is per-trigger and cumulative within the turn: three Humans entering means +3/+3, so the ceiling scales with how explosive your development is rather than how much mana you sink into it. That makes it a payoff card rather than an engine, and a temporary one, since the pump evaporates at end of turn: it does not permanently outgrow removal, and because the buff usually lands during your own sorcery-speed development, the creature is back to a 2/2 by the time your opponent's attackers arrive. Compare it to a static lord, which makes your whole team bigger the instant it resolves and keeps it there; this only grows when other Humans arrive, rewarding a wide chain-of-entries turn and punishing you for casting it late into an empty board. That timing dependency is the whole design: a common built to reward committing to a tribe hard rather than splashing it, a role player whose worth is entirely a function of how many other Humans are riding shotgun.