Skybreen is a common Plane — Kaldheim card from Planechase Planes (OHOP), collector number 35. Current market price: $1.76, TCGplayer market prices via Scryfall.
Players play with the top card of their libraries revealed. Spells that share a card type with the top card of a library can't be cast. Whenever chaos ensues, target player loses life equal to the number of cards in their hand.