I've actually got one 6-layer cel, myself.  Not 
nearly as nice as that Kaioshin cel, nor does it 
have a background, though.  Most of the layers 
aren't very interesting..

1 - Yuusuke's mouth
2 - Papa's head
3 - Papa's body
4 - Gabriel
5 - Miruru
6 - Yuusuke, Sara, Miruru, and the couch.

Makes for quite a thick cel!