Storm, Force of Nature is a mythic Legendary Creature — Mutant Hero card from Secret Lair Drop (SLD), collector number 1742. Current market price: $20.64, TCGplayer market prices via Scryfall.
Flying, vigilance Ceaseless Tempest — Whenever Storm deals combat damage to a player, the next instant or sorcery spell you cast this turn has storm. (When you cast it, copy it for each spell cast before it this turn. You may choose new targets for the copies.)