Pain's Crystal is a Stout Set, it provides a boost to the ATK of all Stout type creatures.
Pain's Crystal I - Stout +5 ATK:[]
Pain's Crystal II - Stout +18 ATK:[]
Pain's Crystal III - Stout +28 ATK:[]
Pain's Crystal IV - Stout +40 ATK:[]
Pain's Crystal V - Stout +35 ATK:[]
