Shining Shoal is a rare Instant — Arcane card from Betrayers of Kamigawa (BOK), collector number 21. Current market price: $2.16 (foil $4.40), TCGplayer market prices via Scryfall.
You may exile a white card with mana value X from your hand rather than pay this spell's mana cost. The next X damage that a source of your choice would deal to you and/or creatures you control this turn is dealt to any target instead.