Bygone Bishop

Investigate as a recurring engine rather than a one-shot reward: that is the design problem this Spirit solves. The keyword usually shows up stapled to a single spell, a one-time Clue and done. Here it triggers off a behavior a white deck would already want to commit to, casting cheap creatures, so the curve that builds the board doubles as a draw engine. The mana value 3 or less clause does the balancing work, paying off the bottom of the curve specifically, the one-drops and two-drops that aggressive white decks flood the board with anyway, and declining to reward the expensive bombs that would not need the help. The lag lives in the Clues themselves: each one banks card advantage you have to pay two mana and a sacrifice to unlock, so the engine can sit on a 2/3 flyer for three mana without warping a fair game. You are always trading present tempo for future cards, whether you crack the Clues immediately or hold them for a lull. The flying body gives the deck an evasive clock that keeps pressure on while the tokens accumulate. It is a deckbuilding incentive wearing a creature's clothes, asking you to lean harder into the low end of your curve than you otherwise might, and refueling the kind of go-wide aggression that rarely gets to refuel at all.