Flashlight? Assuming you mean the move he takes off his glasses, the entire game goes into slow-mo, and you do some epic looking screen-sized, slash (aka his Arc Drive), seriously, don't bother with that. Work on your combos instead.
Since you use Shiki (fruit knife glasses guy), you can start practising on the most basic of combos in MBAA:
Down+A, Down+B, Down+C, C, jump B, jump C, jump B, jump C, air throw.