As usual with status-based shotguns, the most important goal is to reach 100% Status Chance before Multi-shot is calculated. This can be achieved by adding a minimum of +177.8% Status Chance to Exergis (three 60/60 elemental mods without a Riven, two with an average Riven, only ONE with a perfect Riven). Once you hit that 100% sweet spot, every pellet will proc on every shot.
The standard 100% status build. Vicious spread currently has no negative effects on exergis. Ammo Stock, and Chilling Reload are entirely optional, but highly recommended. You can swap Vicious Spread for Vigilante Armaments for an extra ~2/3 procs per shot, and Scattering Inferno can be replaced with Shell Shock if preferred. Be wary of adding more elemental damage than necessary, as it will dilute your proc pool and make Slash/Viral less likely to occur. Adding +Damage% or +Multishot% instead of +Elemental% will raise overall DPS without altering the status proc ratio.
A ++/- Riven with over 117.8% Status Chance and as much Multishot as possible, with a relatively-harmless negative (-Puncture/-Impact/-Zoom/-Ammo are ideal). Ammo pool is reduced to 24 shots on this one, which proves to be more than enough for the weapon's abysmal effective rate-of-fire. 13 procs per shot with Hell's Chamber and Vigilante Armaments.
The Riven build. Green stats on the left reflect the improvements over the basic build. The second and third status mods have been removed, and the third elemental type is gone. Slash procs are the priority! Absolutely no more elemental damage than necessary.
Reaching 100% Status Chance before Multishot
No Riven: +177.8% SC needed = 3x 60/60 Elementals (Toxic Barrage/Frigid Blast/Shell Shock/Scattering Inferno)
>57.8% SC Riven: +120% SC needed = 2x 60/60 Elementals (saves one slot and optimizes proc pool toward Slash and your desired combo element)
>117.8% SC Riven: +60% SC needed = 1x 60/60 Elemental (saves TWO slots, optimizes proc pool, allows Viral to be created with Chilling Reload)
Multishot Mods & Proc Count
No Multishot: 3 procs per shot.
Hell's Chamber: 6 procs, 60% chance of 7 procs.
Hell's Chamber + Vigilante Armaments: 8 procs, 40% chance of 9 procs.
- Vicious Spread / Tainted Shell / Narrow Barrel / Double-Barrel Drift: The +Accuracy and -Spread mods have no noticeable effects. I'm unsure if this is a bug or intentional. It kinda sucks, but it also means that Vicious Spread's curse stat has no effect either! This offers lots of extra damage with no consequence. If Exergis is patched to be affected properly by these mods, Vicious Spread will become completely nonviable, and Tainted Shell will become a very attractive choice.
- Corrosive Procs: Due to the low pellet count and low number of procs per-shot, Corrosive status is inherently less effective on Exergis than other 100% SC shotguns. Viral becomes the ultimate choice for high-level one-shot nuking. Ideally: a single Viral proc will half an enemy's HP, then a handful of Slash procs will chip away at their remaining health, ignoring Armor/Shields.
- Chilling Reload: This will bring your Reload time down to 1.1 second, and can be combined with Toxic Barrage to create Viral. Combine with Ammo Stock for a satisfying boost in effective rate-of-fire.
- Ammo Stock: The magazine size can be increased to two shots. Normally I would never recommend "wasting" a slot on such a mod, but Exergis is a special case.
- Seeking Fury / Seeking Force: Unnecessary. Exergis has 0.5m of innate Punch Through, which is just barely enough to pierce most humanoid enemies (including Shield Lancers). You'll rarely need more. This allows you a free slot that would have otherwise gone to an obligatory core mod!
- Blunderbuss: Never use this. The extra 7.2% Crit Chance is not worth it.
- (Primed) Ravage: Situationally-useful at best, with flat crit buffs like Adarza Kavat's Cat's Eye/Harrow's Covenant/Arcane Avenger. You probably shouldn't bother equipping this though. Exergis has one of the most pitifully-low CD multipliers in the game, and Primed Ravage only raises it to a meager 2.9x.
- Sweeping Serration: Probably never worth it, since Slash is less than half of the base damage. Although this will make Slash more likely to proc.