Immersturm is a common Plane — Valla card from Planechase Anthology Planes (OPCA), collector number 38. Current market price: $3.27, TCGplayer market prices via Scryfall.
Whenever a creature enters, that creature's controller may have it deal damage equal to its power to any target of their choice. Whenever chaos ensues, exile target creature, then return it to the battlefield under its owner's control.