This is genius! That absolutely worked for me. I mash quick up until the 2-3 hit of the grand viper and just let go. Sol took over from there. The mash window must end just as the extra hits of GV start. >< Nice find man.
A lot of haku's move scrape the ground and will catch your 3c. Be extremely careful with this move or risk losing 3-5k every attempt. >< My buddy's haku is pretty damn good at catching my 3C's sadly. lol.