Archon Shards:
1 (Tau or otherwise) Violet [Equilibrium] effect.
2 (Normal) Emerald to increase maximum corrosive stack to 14 for full armor strip with [Archon Continuity] and Silken Stride's Tox damage.
2 (Tau) Emerald to +Toxin damage.

Wall latch before casting 4 for extra health, then hit 3 to Nourish with full Bellicose, to maximise power strength.

I personally prefer Nourish over 3 to not have to worry about the pathing of the scuttlers, instead going for the Viral status effect. If you use a viral primer, feel free to skip Helminth. The scuttlers will do more damage than the bonus% from Nourish adds, and increase chances to use Mercy's Kiss for more universal orbs.

A variant build based on Auncore's Scaling Spider (https://overframe.gg/build/859032/oraxia/arachnophobia-the-scaling-spider-steel-path-general-use/) and nyx1r1z ' Gloomstalker (https://overframe.gg/build/858819/oraxia/gloomstalker-oraxia-black-widow-meets-steelpath/) because I am a simpler person.