Essence Leak

A tax aura with a hard color requirement: it does nothing against a permanent that is neither red nor green, and on a colorless permanent it just sits there inert. Aimed at a red or green threat, it forces a recurring upkeep toll equal to the enchanted permanent's full printed mana cost. Each turn the opponent either pays that cost again or sacrifices the permanent, which makes the aura less a removal spell than a standing rent: a slow, repeating drain on the mana an opponent would otherwise spend developing. The teeth of the design are in the word "mana cost" rather than a flat number. Payment is the printed pips, so an opponent short on the right colors can be locked out of keeping a creature even when its converted total looks trivial, while a heavy multicolor bomb bites far harder than a single-pip mana dork. The card scales its own relevance to the size and color demands of its target. That same conditionality is why it never traveled past the gold-heavy environment it was built for: an answer that whiffs against half the color pie is dead weight in any deck not actively betting on red or green, and a single Disenchant effect trades cleanly for it. The color-hosed hate aura was a lever that early allied-versus-enemy multicolor design used to push color identity down to the card level rather than leaving it in the manabase, rewarding a deck for committing to the enemy of its opponent's two colors.