Monument to Endurance is a rare Artifact card from Aetherdrift Promos (PDFT), collector number 237p. Current market price: $18.43 (foil $16.85), TCGplayer market prices via Scryfall.
Whenever you discard a card, choose one that hasn't been chosen this turn — • Draw a card. • Create a Treasure token. • Each opponent loses 3 life.