The Kenriths' Royal Funeral is a rare Legendary Enchantment card from March of the Machine: The Aftermath (MAT), collector number 169. Current market price: $0.26 (foil $0.37), TCGplayer market prices via Scryfall.
When The Kenriths' Royal Funeral enters, exile up to two target legendary creature cards from your graveyard. You draw X cards and you lose X life, where X is the greatest mana value among cards exiled this way. Legendary spells you cast cost {1} less to cast for each card exiled with The Kenriths' Royal Funeral.