In the coming Shadow Egg, you will have a chance to obtain 3 types of Shadow Box when a Shadow Egg is used. The 3 boxes are Expanded Class Shadow Box, 2nd Class Shadow Box and 1st Class Shadow Box. When a shadow box is opened, you'll received a random piece of Shadow Equipment from it. What can be obtained from the shadow boxes are listed below. 

Tier S Category

Tier A Category

Tier B Category