Lucina’s sword abilities are pretty lethal and a good slash would be enough to take Fox down. Luckily for Fox, his speed is enough for him to dodge her attacks long enough to land some hits with his laser blaster. Lucina won’t be able to block such an overwhelming onslaught of attacks and the hits will add up until she is down for the count. Fox wins.
DReager1.com 
Fox Mccloud. Much better weapons and a level head spell doom for poor Lucy.
I won’t deny it. A shame since she’s such a likable character!