Talk:H Episode 22: Unorthodox Arts, Shoraiabare Kandachi!/@comment-3974145-20150905095504/@comment-6102960-20150905140024

That is the animation staff adding an electric effect (Like the nerves giving you a little "shock" when you feel pain), so it isn't Gao just dropping the deck like he has stomach ache all of a sudden.

Electric effects can be used that way. They used red electricity to showcase recoil damage from Flare Blitz in the Pokemon anime.