I built this as a knockback-free sidearm to carry my lazy ass through steel path, because the knockdown on my otherwise amazing [Sporelacer] was frustrating on some frames.

It's based on the [Phantasma] and [Phage] status builds, and similarly takes advantage of the awesome way status, multishot, and continuous beam weapons interact. The "DPS" indicated by overframe calc is misleading, you'll be melting virally weakened bad dudes with the ridonk heat stacks like it was carrying a much bigger number.

You get 28.1%×19.2(rate)×19.5(multi) or ~105 status applications per second firing, across up to 5 targets.
The damage breakdown means you get about half heat, one third viral. On average, 53 heat, 36 viral, 7 slash, 6 puncture, and 3 impact procs pre second. I've toyed with the idea of using something like [Carnis Stinger] to bulk up slash procs, but haven't tried it yet. Heat and viral gets the job done.

I use Pax Charge for quality of life. Never running out of ammo is worth a second spent not firing now and then. The combination of a large clip size, Pax Charge reload time reduction, and Secondary Merciless reload time reduction makes for a very fast charge. If you want to hold the trigger down longer, swap for a different arcane.

You could trade out faction mod for [Hornet Strike]. This still works fine, and is easier to get started. You lose the status tick double dipping on faction damage, and it wont be as good at the top end on the path.

I appreciate the work that @Arsonistic did on data gathering for the modular weapons, and started out by trying their excellent crit vermisplicer secondary build found here https://overframe.gg/build/107555/vermisplicer/secondary-viralheat-vermisplicer/ and the analysis they've published here https://docs.google.com/document/d/1-74HS0rFLwRxDG4wz4PBRYEnQP2mzgis9HcD7nYGhKs
I dont think Arsonistics model quite captures the feedback loops of high status stacks on high armour mobs, and their model undervalues status procs as a result. I found this status build to be more effective than the crit/damage build for high armour mobs in practice, despite being much weaker on paper. Blame DE voodoo math.