In a 1v1 situation, silence him with running blast and deal damage until he uses emitter, then channel recharge towards him until he runs out of shields then finish him. Nimble would be perfect to keep pressure on him if he tries to run away.

Using your Runic Burst to force reload is great for stopping Ruckus from spamming bullets. Watch your shields though, especially if the Ruckus is carrying Wrecker.

use cover to get close and then use runic blast, shield recharge(if his shields are up), lock on attack(until he starts shield melting you). then move to other targets and into cover

Grab Resilience to counter Torvald's Runic Burst and Hyper Beam, and Wrecker or Deft Hands to shred through his shields.