Reaper of Flight Moonsilver is a uncommon Creature — Angel card from Shadows over Innistrad (SOI), collector number 36. Current market price: $0.13 (foil $0.44), TCGplayer market prices via Scryfall.
Flying Delirium — Sacrifice another creature: This creature gets +2/+1 until end of turn. Activate only if there are four or more card types among cards in your graveyard.