So, I've ever only cleared a Simulacrum with a mirror+ Original Sin STR Stacking Reave build - but it seems the CI Flicker Trickster can do it with badly self-crafted gear and an Ephemeral Edge with Resolute Technique.. I'm not even crit immune ('only' ailment and bleed) and this final wave had the crit mod, Kosis didn't even scratch me? Guess I know what I'll be farming the next few days!

Path of Building: https://pobb.in/Yu8HwoWdh5rM

Full build guide from Tarekis here: https://www.pathofexile.com/forum/view-thread/3472898