Ruckus is safe from CC when ulting, so unless he's low at the end of it, save yours until he finishes. If Ruckus pops his Emitter, try to save your Magic Marks until it ends, or continue to rip though him if you have the upper hand.
Expect the combo whenever he uses Thrust. Use your Magic Barrier to negate his burst. You can run Fluffy 4 or combine fluffy 1-3 with blast shields to make yourself a 4 hit kill with directs unless Drogoz is running Fusillade.
A bad MU. BK will out-burst you most of the time, so make use of the momentum you gain after cancelling a scamper and B-Hop while strafing and shooting. This technique is best utilized in flat, open areas, such as "Garden" In Brightmarsh.