Mystic Subdual

The instant-speed answer to the modern problem of the ability-loaded threat. Where older removal asked "how do I kill this?", this Aura asks "how do I turn this back into a vanilla body?", and against a creature whose danger lives entirely in its text (a flying keyword-soup mythic, an activated-ability engine, a mutate pile stacked with triggers) that reframing is the entire point. Stripping abilities is a cleaner solution than damage or destruction against certain threats: the creature is not dying, so there is no death trigger to feed and no indestructibility to work around, just a body reduced to stats. It cannot do everything a kill spell can, though: because an Aura targets when cast, it cannot land on a hexproof creature or one with protection from blue, which shrugs the enchantment off. The -2/-0 is the tell that this is meant to blank an attacker rather than trade with a wall; it shaves the offense while the loss of abilities does the real work, and the parenthetical about mutation points at the environment it was built alongside, where a single mutated creature could carry a stack of triggers this flattens in one card. Flash is what makes it a control tool rather than a proactive one: held up, it answers a threat during the opponent's untapped window or ambushes an attacker mid-combat. The catch is timing in both directions. It does not counter an ability already on the stack, so it removes what a creature can do, not what it has already done; and because a subdued creature can still gain abilities afterward, it neutralizes what is on the board, not what the board might become.