Came across Shin Lim doing this double fan. Looks like he is springing the cards from a faro shuffle, then using his thumb and and pointer finger to hold the cards like a rifle fan. I've never witnessed this move anywhere. My jaw on the floor. Here is the link.....
https://www.facebook.com/193811114017431/posts/2381495525248968/?sfnsn=mo
https://www.facebook.com/193811114017431/posts/2381495525248968/?sfnsn=mo