Precipitous Drop

Removal that scales with your progress through a side board most of your removal spells can't see: the pitch is a shrink that comes packaged as an Aura, which means it commits ahead of combat rather than answering it, and it ships you a venture trigger on the way in. The base -2/-2 kills most early bodies and cripples the rest, but the interesting part is the retroactive clause. Once you've completed a dungeon, this Aura, and every copy you cast afterward, quietly upgrades to -5/-5, a shift keyed not to anything on the battlefield but to a completed dungeon sitting off in a zone your board can't touch. That is an unusual place to hang a modifier: the removal's numbers depend on a board state that lives entirely outside the game's normal board. The design also solves a tension the venture strategy runs into constantly, which is that crawling the dungeon usually costs you cards that do nothing else. Stapling a shrink to the venture trigger lets one card clear a blocker and advance the crawl in the same motion, with the payoff deferred: finish a dungeon and this becomes a five-point swing on your turn. Interaction that doubles as progress is exactly what a venture deck is short on, and this folds both jobs into a single Aura.