The best possible build with everything in mind.
Edit: Changed the build around Emerald shards.

Ability Strength: Affects your pixia's damage directly. Need at least 200 for pillage. With this build you will have %304 for your Razorwing. Note that if you check the total damage of your pistols in Arsenal while using [Precision Intensify], it will not calculate the %90 bonus. However it's still there and contributes to the damage. (Tested)

Ability Range: Literally useless except Thermal Sunder builds to nuke low levels. Which then you need to swap Precision Intensify with Umbral Intensify and build around more range.

Ability Duration: More the better. It makes your 4th use less energy per second. Duration is more import than Efficiency so your other skills will last longer. Also Pillage range scales from duration.

Ability Efficiency: [Boreal's Hatred] over [Streamline], cuz %15 difference doesn't hurt in exchange you get 0.4s extra shield gate duration when you replenish your shields via Pillage.

I use Primed Flow, it's not necessary but heavily recommended. Flow is also okay and uses one less forma, but it's good to have if you have it maxed already since we will also use a yellow Archon shard to start with high energy pool.

Other helminth options are: Dispensary, which is good for Free Roams and Index. Personally I use it with Equilibrium instead of Razorwing Blitz inside the Index and cast it every time when it's depleted. BE CAREFUL, USING DISPENSARY INSIDE THE INDEX STOPS ALL ENERGY DISPENSERS TO SPAWN ENERGY, FOR ALL PLAYERS. But, as long as you got some energy from the ground dispensers at first, you dont need to worry. Still, be careful and don't run out of energy completely. If you don't have enough to cast Dispensary, you and your squad wont be able to get energy for the whole index run, at all!

[Dex Pixia] build: We will go with Toxin so we can apply Corrosive with Archon Continuity : https://overframe.gg/build/664302/

Arcanes: Arcane Avenger is needed for crit pixia build. Your pixies can also proc Arcane Precision

Archon Shards:
2 Emerald shards to higher the Corrosive cap, doesn't need to be Tauforged since the cap is 14 to fully strip. However Tauforged (6 extra stack) helps with enemies that naturally only takes 4 status stacks. If you're thinking it will massively help with necramechs etc unfortunately, it wont. Their numbers are so absurd that 4 stacks vs 10 is not THAT noticeable. But DE said they will change this in the future, Which will make the Tauforged really worth when it happens.

1 Crimson shard is needed to 2 cast to fully strip. And more strength is just a bonus.

I'd recommend 1 Tauforged Amber shard for starting energy, since we will not be using Preparation or Zenurik And 1 more Tauforged for energy orb effectiveness. This will help us for times that you need to spam Pillage in emergencies.

Companion: https://overframe.gg/build/355010/

Focus School: Be sure to way bound Unairu and always use Madurai. The first skill void strike is the only thing you can get more ammo efficiency, aside from Arcane Pistoleer but other arcanes are hard to pass on.