SP [Oraxia] build.

There's not much to explain here honestly. Her kit is pretty straight forward.

[Growing Power] can be replaced with Summoner's Wrath but I don't think it's quite worth using. The spiders may look like good damage in the simulacrum, but in practice, they're not as good. That being said, they do draw aggro so it might be worth keeping. Otherwise, go ahead and subsume it.

Be sure to use [Archon Continuity] since all her abilities do toxin damage.

[Adaptation] can be replaced with [Rolling Guard] or [Catalyzing Shields]. If you are using [Catalyzing Shields], feel free to replace [Stretch] with [Augur Reach] and [Power Drift] with [Cunning Drift] to get the same range. The 15% extra power strength from [Power Drift] isn't going to change too much imo.

Arcane Crepuscular for the extra 30% ability strength and +3x final crit damage when invisible which hopefully you will be since you'll be wall latching.
Arcane Bellicose will give you a 70% ability strength when you use your 4 on this build, but that additional 70% does not apply to the 4th ability stats itself since you are activating your 4th ability before the additional health is applied and the arcane takes effect.
In other words, the bonus 70% will only apply to your first 3 abilities. Think of it as an inverse [Precision Intensify] in this case. For this reason, I'd rather just use Molt Augmented to apply on all abilities, however you can replace it for Arcane Arachne if you wish.

I put 1 red Tau archon shard for extra duration. The rest is up to you. I think there's an issue with the spiders not being affected by the additional corrosive stack from green shards, so at this time, don't put that on just yet. Maybe DE will update it later.
You can also put Tau purple shards to replace [Equilibrium]. It'll free up an extra slot for whatever mod you want, probably an augment mod that DE will eventually make for [Oraxia].