Boros Challenger

Two mana for a 2/3 that grows the team and grows itself: this is the rare aggressive two-drop that stays relevant past turn four. The Mentor trigger is what pays for the body. A 2/3 is small enough to put plenty of one-power attackers below it, so every swing buys a permanent counter for a token, a one-drop, or a battered creature dropped under threshold, turning a wide board into a steepening problem. The mana sink solves the other half of the equation that usually dooms small aggressive creatures: the late-game dead draw. Once your hand empties, the activation lets you pump it turn after turn, and because Mentor cares about relative power, every swing it makes also pushes that "lesser power" line higher, so the engine feeds itself. The cost of the sink, four mana for a temporary +1/+1, is steep enough that it never crowds out the proactive game plan; it is insurance, not a primary line. That combination, a fair attacking statline, a mechanic that rewards a wide board, and a built-in floor against flooding out, makes this a clean expression of what a two-color aggressive midrange creature wants to be: cheap when you are ahead, useful when you are behind.