Twilight Prophet

The engine hinges on a wager whose payout you never fully control: once the ascend condition flips, every upkeep reveals whatever sits atop your deck and turns it into a drain scaled to that card's mana value. Reveal a fat spell and you swing the race by five while refilling your hand with a finisher in the same trigger; reveal a land (mana value zero) and you drain for nothing, shrug, and try again next turn. That variance is the design's whole argument, and it pulls deckbuilding in two directions at once. The ten-permanent gate rewards going wide and low, but the drain rewards a curve top-heavy enough that the revealed mana value bites. Threading that tension separates a Prophet that stalls out from one that closes a game across a handful of upkeeps. This is a rare drain effect that scales with your curve rather than your board, which makes it a different animal from the fixed-cost school of repeatable black card advantage: those pay a set life for a set card, while this one pays you (and punishes the opponent) on a sliding scale you commit to in construction, not in play. The 2/4 flying body is built to survive rather than to pressure: a defensive shell whose only job is keeping the upkeep trigger alive long enough to matter.