Futae no Kiwami

Sanosuke in Rurouni Kenshin tries to use it against Makoto Shishio (CCO).

This move was also mastered by Sanosuke in a week while it took Anji to do it in a few years. Basically you use the part of body to do two hits one after another in a few milliseconds. The first attack lowers the resistance for the second attack, which is the full force blow. Very handy technique for making defensive air shields, breaking down walls, or just plain old beating the stuffing out of someone. Sanosuke can only use this with his right fist, while Anji can use this with all parts of his body.

FUTAE NO KIWAMI AAAAAAHHHHHH