Case of the Gateway Express is a uncommon Enchantment — Case card from Murders at Karlov Manor (MKM), collector number 8. Current market price: $0.22 (foil $0.23), TCGplayer market prices via Scryfall.
When this Case enters, choose target creature you don't control. Each creature you control deals 1 damage to that creature. To solve — Three or more creatures attacked this turn. (If unsolved, solve at the beginning of your end step.) Solved — Creatures you control get +1/+0.