Fusillade is good against flanks if you can hit the direct shots. Flanks are basicly 2hit kills. If you cant hit direct shots, just practice! Best way to practice is on Onslaught.

If you encounter Strix as Kinessa, wait until he comes out of his Stealth and use a card that reveals enemys on hit for about 2 seconds to outplay other snipers.

Map Brightmarsh. You can dash over the Roof where the capturepoint is. Good to surprise and flank someone from behind/above. Also works with Evie,Drogoz,Maeve maybe even Willo (didnt tryed with willo yet)