[Vadarya Prime]'s unique effect is that every shot you hit creates a zone around enemies that zap enemies with lightning strikes. The lightning strikes scale with mods so I have opted to use [Primary Acuity]. This enables us to all in on critical chance and damage. This build is for if you like gunplay.

[Amalgam Serration]: essential base damage mod, run Spectral Serration as this is synergistic with my [Chroma] build. You can also run this if you are capable of going invisible.
[Galvanized Scope]: increases the critical chance to Tier 3 red crits.
[Vital Sense]: vital critical damage mod
[Critical Delay]: vital critical chance mod (the Fire Rate decrease can be offset, read Additional Notes for more.)
[Primary Acuity]: Increases critical chance and damage on precision blows massively
[Thermite Rounds]: mod to fuse with [Primed Cryo Rounds] to create Blast, to give it some AOE.
[Primed Cryo Rounds]: essential base damage mod that fuses to create Blast.
[Hammer Shot]: increases the consistency of the blast procs.
[Vigilante Supplies]: flex slot but I went with this for the potential critical bump, run whatever you like

Deadhead: base damage and headshot multiplier arcane

Additional Notes:
Lightning strike kills WILL refresh Evade if the initial shot was a headshot.
I am running [Reinforced Bond] on [Wyrm Prime] (but any companion will do) for the Fire Rate increase, in order to free up a slot for Fire Rate; as well as [Tenacious Bond], to increase Final Critical Damage.
[Xata]'s Whisper allows for a more reliable stackless oneshot. External buffs help this rifle greatly, alongside things like Tauforged Violet Archon shards for primary electricity damage. More of these will increase your baseline damage for more consistent oneshots.