The Fluctus's blueprint can be researched from the Tenno Lab in the dojo. Its parts can be purchased from various Syndicates. All parts, except for the blueprint, are tradeable.
The Fluctus' large projectile hitbox makes it a good mid-ranged crowd-control weapon especially when doing Archwing Interception and Defense missions as enemies come in in waves.
The Fluctus' projectiles also bypass the barriers protecting Shield Dargyns (and their Hellion counterparts) from front attacks, giving the weapon an edge over most Archguns when dealing with such units.
This also allows players to safely defeat them from range instead of trying to go into melee, as getting into contact with their shields will cause Electricity damage that can become particularly fatal at higher levels.
Tips[]
Due to its infinite punch through, the Fluctus is a viable option as a Necramech weapon for Orphix runs as it can easily hit the Resonators that are hiding behind barriers.
Trivia[]
The Fluctus Leak during Update 15.6.1.
The Fluctus (along with the Centaur and the Itzal) were accidentally leaked in Hotfix 15.6.1 (2014-12-11), where a bundle called the "Itzal Raider Pack" visually replaced the Stealth Pack in the Market. The Stealth Bundle still functioned as normal, however.
Curiously the bundle referred to the Fluctus as a crossbow.
Fluctus is a Latin word, which is most commonly translated to "waves".
The Fluctus fires horizontal projectiles, despite having a vertical shape.
The Fluctus is tied with the Cyngas for the second-highest per-shot damage among Archguns, after the Velocitus.
At release, elemental mods didn't work on the Fluctus. This was fixed as of Update 15.10 (2015-01-15).
With the various buffs and adjustments we’ve made to Warframe weapons over the years, a common question we see in response is “but what about Archguns?”. These Heavy Weapons are meant to be heavy-hitters, but arguably have been overshadowed by the Primary and Secondary guns in your Arsenal. To address this feedback, we have made the following changes:
ON-DEPLOY OVERGUARD BUFF
Upon using an Archgun Deployer, players will now gain 2000 Overguard.
Effect has a 60s cooldown.
The Overguard gain is capped at 2000, so re-deploying your Archgun after the cooldown resets will refresh your Overguard up to the 2000 cap.
HEAVY WEAPON BUFFS
Overall, most Heavy Weapons (a.k.a. Archguns when used via the Archgun Deployer) have had their damage doubled. Some of the Archguns have also received buffs to their Archwing version, which we will indicate below.
Archgun Damage Resistance
Before we get into the stats, we have added a 50% Archgun Damage Resistance to the Profit Taker. Since these weapons have had their damage buffed, this resistance keeps these fights to the same difficulty as before.
Heavy Weapon Stat Changes Note: these apply only to Archgun Deployer versions of these weapons unless otherwise specified.
Fixed Clients not being able to reliably hit weak-points on enemies (such as the Orphix) with weapons that have sweeping projectiles such as the Fluctus.
Removed the dissolve FX when equipping your Atmosphere Arch-Gun.
Update 24.2 (2018-12-18) ‘ATMOSPHERE’ ARCH-GUN WEAPONS
It’s time we equipped some serious floor firepower! All Arch-Guns can be used on the ground - or as we like to call it ‘Atmosphere’ - with the use of a ‘Gravimag’. Gravimag is obtained from Clan Research, or as a one-time reward from the Orb Heist Phase 3 Bounty, and can be installed on any Arch-Gun (with an Orokin Catalyst installed) via the Upgrade Arsenal - similar to installing a Catalyst.
Comparable to the Archwing and K-Drive Launchers, a respective Gear item known as the Archweapon Deployer is required to activate your Atmosphere Arch-Gun. The Archweapon Deployer can be obtained by completing the Orb Heist Phase 3 Bounty.
Atmosphere Arch-Gun General Changes:
Atmosphere Arch-Guns consume Ammo as opposed to unlimited Ammo/Battery in Archwing. Specifically new Heavy Ammo Drops which can be found from Corpus enemies in Orb Heist missions. Heavy Ammo Drops also reset the 10 minute cool-down when picked up, or replenish Ammo if needed.
Atmosphere Arch-Gun can be summoned in normal missions with the Archweapon Deployer, but once Ammo has been depleted there is a 10 minute cool-down until you can summon again. The intent here is to allow you moments of beefy damage output, and not become just another Primary/Secondary weapon.
All stat changes are for Atmosphere Arch-Gun mode, Mastery Rank changes are global:
Slash damage.
Barrel
Cephalon Suda Offering
20,000
Stock
Steel Meridian Offering
Limbs
Red Veil Offering
Argon Crystal
50
Market Price: 
Blueprints Price:
3,000
Oxium
Gallium
Salvage
Nano Spores
x1 
x3 
x10 
x30 
x100
Amesha • 
Elytron • 
Itzal • 
Odonata (
Prime)
Cortege • 
Corvas (
Prime) • 
Cyngas • 
Dual Decurion (
Prisma) • 
Fluctus • 
Grattler (
Kuva) • 
Imperator (
Vandal) • 
Kuva Ayanga • 
Larkspur (
Prime) • 
Mandonel • 
Mausolon • 
Morgha • 
Phaedra • 
Velocitus
Agkuza • 
Centaur • 
Kaszas • 
Knux • 
Onorix • 
Rathbone • 
Veritux (
Prisma)
