Playstyle and Tips

The [Regulators Prime] can only be used during [Mesa Prime]'s Peacemaker (4). This build is designed for Index enemies and to [Shred] them. Index enemies have Alloy Armor which takes 75% extra damage from Radiation damage thus we've gone for Radiation. Pretty much just find Index enemy, pull these out, delete Index enemy, and repeat.

Replacements and Changes

This is designed to work with my Gold Digger Mesa Prime build so there's not much that you want to change.
The one change I would suggest as a possibility is swapping [Anemic Agility] for [Primed Expel Corpus] to increase damage against Index enemies.

Shared Configs

Viral Heat Regulators Prime | Universal Shredder | Config A
Radiation Regulators Prime | Index DPS | Config B

Related Builds

Gunslinger Mesa Prime | Peacemakers Build | Config A
Gold Digger Mesa Prime | Index DPS | Config B

All of my builds are theory-crafts as I am currently missing some endgame stuff, and some of my mods aren't maxed but they should all work well and be fun.