The Elderspell is a rare Sorcery card from War of the Spark Promos (PWAR), collector number 89p. Current market price: $0.85 (foil $2.03), TCGplayer market prices via Scryfall.
Destroy any number of target planeswalkers. Choose a planeswalker you control. Put two loyalty counters on it for each planeswalker destroyed this way.