I've yet to see snow raph miss on my end and i had her fire it over 20 times by now... Even her quad debuffs (stun, stun, atk, def) had missed it's atk and def debuffs at least 3 times each by now. Light raph missed at least twice since I had her though, which is twice as long as her snow version
But maybe that's just me. Now if only Jack frost wasn't the opposite cause hers only worked TWICE since I got her