>>410929949
objs are static 3d models, they aren't rigged

that means your ripped character doesn't have a skeleton and the mesh has no weight painting (the deformation values that tell it how much it bends with the skeleton and where). The skeleton might be in the json idk but even if it is still no weights.

You'll have to recreate those from scratch. If you've never worked with 3d before it could be too much. Workshop might be able to help you but starting the blender dungeon with weight painting is going to be very very fun.