a very interesting card indeed, but don't exactly understand the notes
If you have a Skeleton, before it would attack it would have the same effect of being rewound. Then it would attack.
If you have any other creature, before it would attack, it would die and turn into a Skeleton. All death effects would happen except Bone Wall.
So it goes back and for between Skeletons and a random creature, in a musical smörgåsbord.