A very solid build for high level survival missions (especially SP Circulus since nullifiers dont spawn there and you can just chill for few hours without any problems).

What weapons should you play with this build? You dont really need primary or secondary weapon, but for melee Tenet Agendus is a very solid option with many reasons, (high base damage, very high block angle) please check this build too.

For primary weapon you should pick [Miter] with Neutralizing Justice, multishot and firerate mods to pop nullifier fields as fast as possible since they are the only weakness. Make sure to put Primary Dexterity to increase combo duration. Cheap build example.

Adaptation IS MUST HAVE MOD, MAKE SURE YOU HAVE IT!

If you dont have Umbral Intensify just replace it with non-umbral version.

What archon shards should you use? 3 blue +max energy shard (tauforged highly recommended), 2 yellow shards (energy orb effectiveness, and max energy on spawn. If you have 2 tauforged blue shards you can replace third with 1 casting speed shard.

How to play with this build? Extremely easy. Cast 2 on yourself and 3 (to make sure you cast 2 on yourself just lower the mouse to the floor and press 2), kill some enemies with your melee to get combo multiplier and energy, then cast 4 to refresh your 2's duration and then detonate glass with first skill (it's highly recommended to not press 1 button but hold down the key for more damage). After that you will increase your 2's damage by ~250-300k, and now all you have to do is run to tough enemies, cast 4 + 1 again to make your 2 deal even more damage and so on. While your 3 is active it will apply 1 virus stack each 2 seconds if you got damage. Don't forget to recast your 3, it should be active all the time! Shattered Storm will apply damage multiplier to all enemies that didn't die due to your 4+1 combo.
While casting 4 you are fully invincible for mere 3 seconds, use that to dodge some acolytes damage and eximus attacks.

For companion you shoud choose Panzer Vulpaphyla with Synth Fiber mod to pick up healt orbs, with combination of Equilibrium and Nourish from one healt orb you will recieve over 300 energy. Synth Deconstruct will increase amount of healt orbs dropped by enemies.

If you don't have Synth Fiber mod you can swap Steel Charge to Combat Discipline.

Why Arcane Phantasm? Because with this build you will block A LOT (blocking also increases your combo multiplier and high combo will boost your damage from 1st skill) and in high level missions especially SP there will be tough enemies with high armor that will survive your 4 + 1 combo and to kill them you should just get close to them so with extra movement speed from blocking it will be much easier and comfortable to play.

If you don't have Primed Sure Footed you can switch to Handspring, Rush, Speed Drift or Cunning Drift.