UPDATE DEC 2025
Arcane Persistence now allows [Inaros] to basically be immortal even up to levelcap. Arcane Persistence prevents enemies dealing more than 500 damage per second as long as you have over 700 armor. Since [Inaros] has between 4000 to 8000 health depending on how many health mod sources you have, you essentially could stand still for 8 to 16s without healing. Sandstorm heals back 50 health per second for each enemy trapped, scaling off strength, and also makes you invulnerable for the whole sandstorm period. Scarab Shell also makes [Inaros] immune to magnetic, heat and corrosive statuses which are things that can make persistence fail meaning you only need to worry about violence and nullifiers. To hit the armor cap, we have a few options:
1. Stand United + Umbral Fiber + Umbral Vitality + Umbral Intensify: always active non-conditional but takes highest investment (needs TWO umbral forma) but also gives highest stats
2. Stand United + TWO Tau Armor shards: always active non-conditional and saves forma
3. Scarab Shell: conditional, requires it to be active and charged so least safe method but saves multiple mod and archon slots

BUILD SPECIFICS

Duration
Keep positive to improve the uptime of Sandstorm and Scarab Swarm.

Efficiency/Energy Economy
Can dump since we run [Hunter Adrenaline] which constantly gives energy when you take damage (although note you need to be outside of sandstorm).

Range
Keep neutral or positive for the suction radius of sandstorm, although this does not need to be excessive since you can control the direction of the tornado and pick up enemies. The base range of Scarab swarm and Dessication are quite high.

Strength
Strength is needed to boost the armor bonus from Scarab Shell, damage of sandstorm and status chance of [Elemental Sandstorm] (strength essentially double dips sandstorm's status DPS).

Arcanes
Arcane Persistence: needed to make [Inaros] basically immortal in all levels
Arcane Bellicose: gives 72% strength due to high health
Arcane Grace: optional passive health regeneration which scales with max health. You need 8334 health for the 6% health to hit 500hp/s, which exactly counteracts persistence loss rate.

ARCHON SHARDS

For weapon focused Inaros:

• Two or more Crimson Duration shards for sandstorm and roar uptime
• Two or more Violet primary Elec shards for primary weapon focus or Violet melee crit dmg shards for melee weapon focus
• One Cast Speed for roar and scarab swarm animation

To maximise pure sandstorm DPS:

• Two regular Emerald +corrosive stack for full armor strip
• Three Tauforged Emerald +ability damage on corrosive status

If NOT running Triumbral: You need TWO Tauforged Azure armor shards or THREE regular armor shards are required to hit the 700 armor threshold for Arcane Persistence.

ARSENAL

Primary
You can run Primary Bulwark arcane on primary weapons when Scarab Shell is charged up giving a total armor of 1500 to maximise 500% primary damage.

[Coda Hema]: This has lifesteal on headshots with is nice to heal Inaros without being in sandstorm AND has multiplicative Galvanized Aptitude (meaning it multiplies with Primary Bulwark/Serration rather than adds). Sandstorm could also prime additional elements for you.
General Use Build: https://overframe.gg/build/917673/
Thrax Killer Variant: https://overframe.gg/build/949502/

[Torid] Incarnon: Blast Torid works well with grouping

Melee
The elemental mods placed on your melee and the melees base IPS/elemental distribution affects the elemental weighting of [Elemental Sandstorm], and changes how often a status is activated. Melee arcanes such as Melee exposure appear to work, while Melee influence has no specific interaction. Melee mods such as damage, crit, attack speed, status duration do NOT affect Sandstorm at all.

Primer:
If you want your sandstorm to be a pure condition overload/viral primer, simply place viral + heat/electric + radiation + magnetic mods on a weapon with innate corrosive, such as Caustacyst. This will allow sandstorm to proc 6-7 statuses (IPS, corrosive, viral, heat, radiation), which can feed into certain guns that work well with priming and grouping e.g. weapons with multiplicative condition overload effect: Coda Hema, Nataruk/[Cinta], [Lex] incarnon, [Tenet Arca Plasmor].

Blast:
If you want to use Sandstorm alone to passively kill enemies, you can mod a weapon with pure blast and run [Diriga] with [Arc Coil] priming viral and magnetic.
Silva and Aegis Prime is a weapon with pure heat meaning you can mod it for 100% blast with a single cold mod to maximise blast DPS.

Electric Influence:
If you are running a priming companion such as Panzer/[Diriga] that can prime viral for you and would like to do a combination of sandstorm DPS and direct melee DPS, you can simply run a pure electric melee with Melee Influence, which doubles as an [Elemental Sandstorm] DPS statstick AND a DPS melee. Once sandstorm ends, enemies are often grouped and knocked down, making it very easy for the next few melee hits to naturally perform ground finishers. Weapons in the fist, sparring and claws category have the highest ground finisher multiplier of 30x, followed by tonfas at 20x.

[Okina Prime] is one of, if not THE strongest influence light attack melee in the game and has the bonus of boosting movement speed by 30% which affects sandstorm movespeed.
Okina Prime Incarnon: https://overframe.gg/build/668223/

[Furax Wraith] is the strongest fist melee in the game and can use both melee influence and perform ground finishers for 30x multiplier
Furax Wraith Incarnon: https://overframe.gg/build/642135/

Prisma Ohma is the strongest tonfa melee for melee influence (and one of the strongest non-incarnons too) and is innate electric meaning the effect on electric weighting for sandstorm damage is highest. Tonfas also have a 20x ground finisher multiplier.
Prisma Ohma: https://overframe.gg/build/601313