vxdeed asked: I'm still quite confused by this bit of lore: Can RGB, or, any other monster, per say, change their whole bodies with this exchanges?
RGB cannot, other unformed characters may, but it is more usual for them to alter pieces of themselves one step at a time. It’s pretty rare for a character to completely alter their entire appearance from the form they came into the world with, as they must have ‘something’ about them to have maintained their existence and come to the world in the first place.