Lost in Memories is a rare Enchantment — Aura card from Avatar: The Last Airbender Eternal (TLE), collector number 121. Current market price: $0.26 (foil $1.78), TCGplayer market prices via Scryfall.
Flash Enchant creature you control Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost." (You may cast that card from your graveyard for its flashback cost. Then exile it.)