Sure NOW you tell us.... all this time I assumed you meant it was for JA. ; )
You're a sneaky one... !
I'll give it a shot in both games though, as soon as my server empties out.
Update: Amazing in the 1+ year I had my Strategy page up nobody once sent this move in, well I tried it in JA and it works.
"Two Handed Backslash" with Single saber Medium or Strong Stance. Just like you said and it does seem to do more damage than regular backslash.... kills in 1 hit (with saberdamagescale 2) instead of 2 (I guess because this time it's a head shot?).
Anyway, thanks for letting me know about this "old" but never published move, I'll add it to the site at my next convenience.