Expose Evil

Tapping is not removal, which is the whole tension this card lives inside: for two mana at instant speed you buy a turn against two attackers without actually answering either of them, and then you replace the card in your hand with a Clue token that draws later. That second clause is what justifies the rate. A pure two-creature Falter effect at instant speed is a marginal trick, useful in exactly one combat step and dead in your hand the rest of the game; bolting Investigate onto it means the worst case is still a slow cantrip. You tap nothing relevant, you crack the Clue two mana at a time, and the card was never truly blank. Used aggressively, the tap is offense: lock down two would-be blockers and push a lethal swing, then bank the Clue for the grind. Used defensively, it is a stay-of-execution that fogs two attackers and refuels. The design lesson is in how cheaply the floor was raised: investigate is a small enough rider that it can be stapled to an otherwise situational effect to make that effect always castable, the same structural job a cantrip does for a counterspell. What looks like a tempo-and-value combo trick is really a card that solved its own greatest weakness (uselessness in topdeck mode) by paying you a card for casting it whenever the tap is irrelevant.