Not your standard [Sobek] build, is it? No Cleanse mod; built for Heat; and named for [Caliban]? Allow me to explain.

Acid Shells is the bread and butter of Sobek, capable of turning a single target shotgun into a room-wide devastating nuke, if you can manipulate some key factors:

1. Armor -- This is a factor that can't be ignored unless you're using Slash procs or True damage. Acid Shells does neither, so it will have the damage it deals reduced based on this value.
2. Faction -- [Acid Shells] is normally unaffected by mods directly. However, modifiers that can deal Faction damage (such as Cleanse mods and Rhino's Roar ability) will allow for an increase in the % damage Acid Shells will deal.
3. Viral -- Let's face it, everything gets better with Viral. Just a single proc doubles damage to HP from all sources.
4. Miscellaneous Debuffs -- Several Warframes (and even Helminth) have the ability to apply a debuff(s) that enhances damage dealt to enemies outside of factors described above.

So where do we go from here? Enter Nourish Caliban:
https://overframe.gg/build/420754/caliban/acid-shells-nuke-king-nourish-caliban/

Let's check off the boxes as we go:

Armor: ✅
[Caliban]'s fourth Ability, Fusion Strike, creates a fallout zone capable of stripping Armor and Shields, up to 100% if Ability Strength is at 200%+. And it can create as many zones as you can afford to spend Energy on. So we got this covered.

Faction: ❎
The purpose of the build is to be a universal nuke. As it stands, we have a few Factions in existence that do not have a mod to benefit against them, such as Narmer. Furthermore, this is a Nourish [Caliban], so Roar is inaccessible without a Specter or a Squadmate.

Viral: ✅
Nourish applies Viral not only to all weapons, but also allies and [Caliban] himself in a defensive pulse when enemies attack. [Caliban] can drop up to 3 Conculysts, as well as have a Companion, and apply this defensive "Viral splash" from Nourish on all of them, effectively spreading forced Viral (and Stagger) procs around the vicinity effortlessly.

Miscellaneous Debuff: ✅
[Caliban]'s second ability, Sentient Wrath, is a combination crowd control + defense debuffer. Assuming your Ability Strength is 200% or higher, enemies caught by Sentient Wrath will have a x1.7+ debuff for the Duration.

With Nourish, [Caliban] ticks off 3 of the 4 boxes, and something as easy as a [Rhino] Specter can solve the issue of the last box, yet it's not even necessary when you look at the calculations below:

First calculation: Viral-buffed Shells
First, assume for sake of calculations that the enemy has been successfully armor stripped due to Fusion Strike.
Between [Caliban], a Companion, and 3 Conculysts (nevermind about extra Squadmates), there's up to 5 targets that could force a Viral proc on enemies. Let's assume some overlap occurs and we have 2 Viral procs on multiple targets when we kill using [Sobek]:

45% of max HP from [Acid Shells]
x2.25 damage multiplier due to Viral
= 101.25% of max HP

This means if you kill the enemy with the highest HP, everyone else falls.

Second calculation: Viral Wrath Shells
One of the intricate details of this build that helps make it so effective is Nourish and [Combat Discipline]. When you kill using [Sobek], it will trigger [Combat Discipline], which in turn triggers Nourish's Viral splash effect, causing enemies around you to be inflicted with a Viral proc. Most importantly, this happens before [Acid Shells] deals the AoE damage. In addition to this, Sentient Wrath offers a solid debuff to further amplify the equation. So if we assume Ability Strength is exactly 200%, we have these numbers:

45% max HP from [Acid Shells]
x2 damage multiplier due to Viral
x1.7 damage multiplier due to Sentient Wrath
=153% of max HP

You could kill virtually anything and wipe the board.

Now as for the Sobek build itself:

-Galvanized Mods
[Sobek] is not an innate AoE weapon, so [Galvanized Savvy] works at full potential, and with up to 5 possible status procs to apply, it will greatly assist in getting kills. [Sobek] also has a strong ammo economy, so we can use Galvanized Acceleration to make it more effective at greater distances. Galvanized Hell speaks for itself.

-Acid Shells
Also self explanatory.

-[Primed Ammo Stock], [Seeking Fury], Arcane Merciless
[Sobek] has an abysmal Reload Speed; these mods cut it down drastically. Having some Punchthrough on Sobek is also a nice QoL stat, and Merciless is easily maintained as Acid Shell kills also apply stacks.

-Shotgun Barrage
Sobek's Fire Rate needs a pick-me-up, so almost doubling it with this mod is highly effective.

-[Scattering Inferno], [Incendiary Coat]
There's multiple purposes to modding for Heat only. One, it's effective against flesh, which is what we'll be dealing with due to armor and shield strip. Two, if it just so happens the enemy did not get stripped of their armor, Heat innately cuts it by 50%. Heat procs also produce panic, so the enemy we focus on will stand in place flailing, giving us opportunity to focus fire on them and net the kill to trigger Acid Shells. We also automatically get Viral through Nourish, so modding for it is a waste of slots comparatively.

-Riven Options
Naturally, consideration of a Riven for [Sobek] is going to occur as it has a high Disposition. Due to the nature of the build, I'd suggest stats such as Multishot, Fire Rate, Heat, Reload Speed, Punchthrough, and/or Damage as higher priority, with Weapon Recoil as your negative.