Glorybringer

A five-drop that lands as both a clock and a removal spell, resolved in a single attack step. Flying and haste mean it pressures the board the moment it hits the table; the exert clause turns that swing into a four-damage bolt aimed at an opposing non-Dragon creature, folding an answer into the same turn the body swings for four in the air. The stated cost (the Dragon stays tapped, unable to attack or block until you untap) barely registers against a threat that already demands an immediate response. The non-Dragon restriction is the only real seam in the design: it keeps a stalled board of mirror-match flyers from being one-sidedly cleared, and it stops the card from trivially picking off other copies of itself. What makes the tension bite is that the removal is optional and gated on attacking. Hold the trigger and simply fly in for four while the board is empty of worthwhile targets, then exert the turn a blocker or a threatening creature appears, and the tempo swing arrives exactly when it hurts most. Most cards built on exert asked whether the payoff justified surrendering the next attack step and answered "sometimes." This one made the surrender feel like an afterthought: a clock, an answer, and an attrition engine that never needs follow-up to earn its slot.