Urn of Godfire

A one-drop that spends its early life running at a deficit. The first ability filters color rather than accelerates it: paying for one mana of any color is a net loss every time you use it, a rate no dedicated fixing artifact would ever pay if fixing were the whole job. What justifies the inefficiency is the button waiting underneath. Six mana plus the tap and the sacrifice turns the rock into a kill spell for a creature or enchantment, telegraphed in the sense that it sits on the board and everyone can see it coming: not repeatable, since the artifact is gone once you fire it, but interaction you get to hold in reserve without spending a card on it. So the design is a patience contract: deploy it on turn one, eat the bad filtering rate in the interim, and cash the artifact in late once you have the mana and a target worth the trade. The two halves are priced against each other deliberately: the expensive, lossy fixing is the tax you pay up front for removal you never have to draw. That makes it a card for long, grindy games rather than tight ones, where a slow filter that eventually becomes a one-shot removal spell earns the seat it takes, and where nobody is counting the mana it quietly loses along the way.