Kaalia of the Vast

The biggest creatures in the game are priced to end games: Angels, Demons, and Dragons sit at six, seven, eight mana and up precisely because they win on impact. The attack trigger pays none of that cost, slamming them onto the battlefield already tapped and attacking. That is the entire design: a four-mana 2/2 that does nothing alone and threatens lethal the moment she is declared as an attacker, with the gap between the small frame and the enormous payoff doing all the work. The attack restriction is what keeps it honest. The ability fires on attack declaration, before blockers, so she has to survive a full turn cycle with every removal spell pointed at her, and the finishers she drops arrive committed to the red zone rather than safe and untapped on defense. The "tapped and attacking" clause makes her a haymaker rather than a value engine: she pulls bombs straight from your hand, not the graveyard, and dumps them into one swing instead of accumulating advantage over time. Flying matters as a survival and damage tool, not a trigger enabler; the trigger fires whether or not anything could block her, so the evasion exists to keep her alive and push the swing through. She is the rare payoff whose three tribes and three colors converge on one combat step that turns a hand of expensive finishers into a kill.