My [Regulators Prime] Build: Infinite Overguard Regulators Prime (4 Forma)

Archon Shards:

• Tau Violet (Purple) - Equilibrium
• Tau Amber (Yellow) - Parkour Velocity, Energy filled on Spawn
• Tau Topaz (Orange) - Secondary Crit Chance (You don't really need these, but it's funny!)

Mods:

• You can still use the "masochist build" with Combat Discipline (Rank 4) and Arcane Avenger, where you self-inflict damage that gets reduced to 0 by your Shatter Shield while constantly triggering Avenger, however Arcane Hot Shot is just objectively superior, granted you have access to it through ETA.
• Like each and every [Mesa] build, the performance of this build heavily relies on Arcane Velocity aka Arcane Mesa, making the build vastly less effective without it.
• Transient Fortitude can be swapped out for Blind Rage if you're willing to deal with higher Energy costs.
• Constitution can be swapped out with Augur Message (-4% Duration) for shield-gating or [Equilibrium] to substitute any [Equilibrium] shards, though if I were to run any of these alternatives, I would probably replace [Primed Redirection] with Primed Sure Footed for knockdown resistance whenever you don't have any Overguard, which isn't a huge issue as most of the shield-gating comes from Secondary Fortifier anyways.
• In level-cap content or with significant debuffs in EDA/ETA, running [Rolling Guard] as a panic button might be worth considering, although the Overguard from Fortifier usually mitigates any need for it.

Playstyle:
Literally press 1, 2, 3 every 60 seconds and use your 4 in combination with the Augment and some Parkour Velocity Shards to roll around and kill everything.
Survivability is great due to Shatter Shield on top of Secondary Fortifier giving you up to 15,000 Overguard, making you effectively invulnerable as long as you have anything with Overguard to shoot at for a millisecond.
Have fun!