Fire Lord Zuko

Firebending X keys off power, which means the more this creature grows the more red mana it dumps into a single combat step: an escalating ritual that only fires while attacking and evaporates when combat ends. The second clause supplies the reason to grow it, rewarding exile-matters play with a team-wide +1/+1 counter whenever you cast a spell from exile or a permanent you control enters from exile. Each counter that lands on the body feeds the next attack's mana, so the engine wants to spiral: cast from exile, pump the whole board, swing, generate a pile of red that only exists for that combat. What complicates the loop is that both halves cohere only if the mana has somewhere to go before combat closes, so the shell around it has to hold instant-speed sinks rather than the exile-cast spells that powered the counters in the first place. Three colors buys the flexibility to run both engines, but it also raises the ask: an exile-value stream to feed the counters, a combat-speed outlet to spend the mana, and enough creatures on the field that a board-wide pump actually matters. The two abilities point in opposite directions, and reconciling them is the design problem the card sets. It reads as a payoff and plays as a puzzle about sequencing a single attack step.