Case of the Gateway Express

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.

Card Details:
Set: Murders at Karlov Manor
Collector Number: 8
Artist: Edgar Sánchez Hidalgo