Alessi has a shadow that turns people back to a child.
In the game, it would revert them back to their old stand.
For example, if you had SPOH and then had Kars, you would revert to your SPOH since it was your old stand.
People with 1 stand, they would turn stand-less of course.
If you have King Crimson, you’d turn back into 2 arms or something you had traded for King Crimson.