Devourlock, of course. Use whatever kinetic you like, I had a Pillager SMG mostly as a backup for when Ruinous got low. Special ammo finders help with that. My rocket is an Apex Predator from the Dreaming City (or Last Wish raid?) with tracking and auto-loading holster.

From the plate, create a Ruinous orb that is en route to the knight. Use the guard action to blind him and all enemies, it also nukes the red bars. When the knight has around 45-55% health left, dunk the Ruinous orb for an insta-kill. Else finish off with Ruinous, since bonus damage (assuming your catalyst is done).

Run back to the plate to calm it down, drop the orb. Kill an ad or two to keep Devour alive and clear the area, then dunk the orb. Boomers appear, jump in the air to avoid ads and rocket them. If they don’t dodge, it should be a OHK. AFAICT, a trick is that if you’re far enough away from them, they don’t try to dodge.

Rinse, repeat.

The real trick I had to figure out was to Ruinous an enemy from the plate en route to my next knight. Doing it while en route took too much time, and the plate would kill me.