Treasure Nabber

A punish card aimed squarely at a habit players don't think of as risky: tapping a mana rock. The triggered ability fires on the act of using an artifact for mana, so it doesn't demand you attack anyone or answer a threat; it just sits on the board and makes everyone's Sol Ring, Signet, and mana dork of an artifact a liability the moment they tap out. The temporary theft is the mechanically interesting part. You don't keep the artifact, so this isn't a permanent swing in resources; you borrow it until the end of your next turn, which means you can tap the stolen rock for your own mana or, better, sacrifice it or feed it to something before control snaps back. That window (their turn, your turn, gone) turns a defensive deterrent into a proactive resource-grab, and against a table stacked with fast mana it can generate a real mana advantage without asking you to cast anything. The 3/2 body is deliberately fragile: this is a creature that wants to be ignored, and the low toughness is the tax for how disruptive the trigger is if left alive. The clock also matters, since the effect keys off opponents choosing to tap, it rewards a metagame read more than a fixed deck slot, punishing exactly the ramp-heavy artifact strategies that treat their rocks as free mana rather than fragile permanents.