Aetherflux Reservoir is a mythic Artifact card from The Brothers' War Retro Artifacts (BRR), collector number 65z. Current market price: — (foil $1,199.00), TCGplayer market prices via Scryfall.
Whenever you cast a spell, you gain 1 life for each spell you've cast this turn. Pay 50 life: This artifact deals 50 damage to any target.