My take on distant Observer's build. His build and ideas work very well, these are just tweaks built around the mods/mod ranks that I have.

Use decaying key + augur for shield gating, should be forma-compatible with the linked build when using aura forma. Can also just use a V polarity aura mod.

I chose [Rejuvenation] to replace Arcane Grace, so that when we do get hit, Arcane Avenger will proc and we will still passively heal (since Steel Charge does nothing for us in this build and Growing Power would be spotty since we shouldn't be shooting/attacking). Could also use Combat Discipline and some medical linking/synth mods on your pet and/or life stealing weapons, but we will lose some of the evasion from sly vulp.

If you don't want to use avenger, I'd recommend arcane barrier/grace/resistance for additional survivability. With the current aura, I'd recommend Arcane Resistance to buff up the effectiveness of the shield gate, but you do you :)

Because we are relying on shield gating (and I had to remove [Vitality] to reliably hit 200% strength), we swap [Adaptation] for [Rolling Guard]. The goal is not to be hit at all, but if we are, to repair the shield gate quickly. When the gate pops, roll and cast The Lost or The Vast Untime. With the decaying key on and augurs, this should reset the gate before [Rolling Guard] wears off. Bonus points if you use Accuse to make the ones who hurt you draw aggro instead, which will also buy you time to cool down Rolling Guard

Recommend Gas Rakta Dark Dagger w/[Argonak] mod. Dagger will help resonator keep aggro even better, and can deal decent damage.

This build is verrrryyyy energy hungry, recommend keeping Zenurik running constantly and using syndicate perks to top up. Fortunately, the [Rakta Dark Dagger] proc (using the syndicate mod) restores energy, and you don't even need to swing it to gain the effect. Just hold it in your hand :)