if you do use it...time it early so you hit them whit the tip of the spark. So you can keep as much range form Lucas's body and the opp. It does more damage the close you are, but it seems to whiff more often and the attack goes behind them and misses :0. Time it early. Go to training and work on it a bit, it's not to hard to pick up.
From my exps tho, you can have good and the still get rock. The attack doesn't seem to have good priority. Use the range. Close 12%, Range 10%, Good knockback at high % even lifts them airborune, not the best Ko threat tho.
Have you tryed?
Dash-shld cancel-s-tilting. Little less range, much faster and a ko threat at decently high %.
or
Short-hop fair or nair?
