Signed Three really stick out, two shotgun kills (Found Verdict & Invective) and one as Bladedancer using arc blade. On all occasions, including kills I haven't listed here, I was really close and had caught the Sunbreakers off guard either by closing the gap rapidly, completely blindsiding them or catching them between hammer throws. In my (limited) experiences it's always been the case that you need to get in close to them to really have a chance.