Mindbreak Trap is a mythic Instant — Trap card from Mystery Booster 2 (MB2), collector number 168. Current market price: $9.04 (foil $113.02), TCGplayer market prices via Scryfall.
If an opponent cast three or more spells this turn, you may pay {0} rather than pay this spell's mana cost. Exile any number of target spells.