The goal of this build, or any good [Vauban] build, is to use what is best about him: make the best you can of Vortex; a no target capped autonomous CC.
Make sure to cast Spectrorage on your Vortex, and let the energy [Flow]. You'll be able to easily maintain Vortex, as well as any other extremely high cost set up someone else may have indefinitely. This also recharges Necramech energy easily.
When used in Circuit, consider Persistent Attrition to be your best friend, making [Flechette] suddenly do unreal damage.