Tip overview

Kill her illusions first so that she can not heal/do dmg/block dmg with it

When you see him use Billow, wait a little while before transporting away because he cannot cancel the ability and transporting away too early gives him time to close the gap on you.

Always select Fusillade when targeting a ruckus, it is very easy to land direct shots on him.

Try to get ruckus low and force him to shield before using your deflect, you can easily do this by out ranging him.

Movement is key! use your dashes to move around him. If you're running low, Reflect so he'll stop shooting. it'll take a little for his gun to start back up, capitalize on that time. When ruckus ults, just deflect it. he usually wont stop.