This is expensive as fuck and I didn't even test is yet since I don't have voruna (and two random umbral forma laying around)
But the synergy with her 3 and equilibrium/[Health Conversion] seems super interesting, just be sure to use a companion with [Synth Fiber] equipped so you can pick up health orbs at max health.
If you did already test a build like this then please tell me how it went...

SO:

Grab a stronk melee. [Glaive Prime] is the obvious choice since it's objectively the best melee in the game but I subjectively recommend [Lesion] too since we need a ton of status for her 3 (yes you can also use her 2 to spread a shitton of status).

**Activate gloom and her 3, set your passive to status immunity** (it's her 2nd ability). as you kill enemies make sure to **use your 2 from time to time** so you keep up the duration on your 3. Or just have a weapon that can apply 5 statuses I don't really care. You get healing from gloom and constant health orb drops from melee kills, this also refills your energy and grants you extra armor.

Arcane energize is optional, you can also replace [Constitution] if you want to use another mod for some reason.

Might be complete shit, we'll see. You never know with health tank builds.