Void

Rat King — Plague Rats (Hunter)

Solo invis-loop survivability + add-clear that never stops vanishing

✓ Manifest Kinetic · Primary · 300 RPM · No intrinsic champion

Weapon: Rat King (Sidearm · Primary · Kinetic) · Subclass: Nightstalker (Void) · Role: Solo invis-loop survivability + add-clear that never stops vanishing Sandbox: 9.7.0 · Created 2026-06-16

Rat King is the invisibility weapon. Reload right after a kill and you vanish; the catalyst heals you every time you do. Most builds treat Rat King's invis as a party trick because it's a Kinetic primary with no obvious subclass home. This one makes it the engine: a Void Hunter where the gun is a third invis source stacked on Vanishing Step and Stylish, every vanish refreshes health, and Graviton Forfeit turns that constant invis into constant ability regen and a free Void Overshield. You play the whole activity translucent.

The weapon

Rat Pack (intrinsic): "This fully automatic weapon becomes stronger when nearby allies also have it equipped. Stacks up to 6 times."

Vermin (trait): "Reloading immediately after a kill grants a brief period of invisibility."

Catalyst — Infestation: "Improved aim assist and recoil direction. Refreshes health on Vermin invisibility trigger."

Mechanically: it's a full-auto 300-RPM Kinetic sidearm with a forgiving Range/AA profile (catalyst smooths recoil further). The damage scaler (Rat Pack) only matters in a fireteam where allies also run Rat King — solo it's a baseline-strong primary, so this build does not lean on the stack count; it leans on Vermin. The kill→reload→invis cadence is the whole point, and the catalyst bolts a heal onto every invis trigger, turning add-clear into self-sustain. The loop is: kill, tap reload, vanish + heal, repeat — indefinitely against any add density.

Loadout

Slot	Pick	Why
Subclass	Nightstalker (Void)	The invisibility subclass — stacks two more invis sources on top of Vermin and makes invis do things.
Super	Shadowshot: Deadfall	Tether groups + 35% weaken; the panic button and an elemental-debuff igniter for Stylish.
Class ability	Gambler's Dodge	Reloads on dodge (re-arms Vermin) and refunds melee near enemies.
Movement	Triple Jump	Air control to reposition while invisible.
Melee	Snare Bomb	On-demand smoke → invis + weaken (debuff for Stylish); also the Void status Trapper's wants.
Grenade	Vortex Grenade	Lingering AoE for kills that feed the Vermin reload; weakens with Undermining.
Aspect 1	Vanishing Step	Dodging makes you invisible — a second invis source that re-loads the mag at the same time (re-arms Vermin).
Aspect 2	Stylish Executioner	Any elemental-debuffed kill → invis + Truesight; next melee while invis weakens. A third invis source off your weaken kills.
Fragments	Echo of Persistence · Echo of Obscurity · Echo of Starvation · Echo of Harvest	See below.
Exotic armour	Graviton Forfeit (Helmet)	Extends every invis, regens grenade/melee/class faster while invisible, Void Overshield at max stacks.
Weapon 2	A Void Special (e.g. a Void shotgun/fusion) — keeps you on-element for surges and an extra weaken/volatile source.
Weapon 3	Heavy: Machine Gun or a Void rocket for bosses/champions the primary can't execute.

Fragments

Echo of Persistence Invisibility/Overshield/Devour last longer — directly extends every Vermin/Vanishing/Stylish vanish and the Graviton overshield
Echo of Obscurity finisher → invis, a free re-trigger and another catalyst heal
Echo of Starvation pick up Orb/Void Breach → Devour — second heal layer under the catalyst
Echo of Harvest (weakened kills → Orb + Void Breach, which feeds Starvation). Snare Bomb / Vortex+Undermining supply the weaken; Harvest converts it to the orbs/breaches Starvation eats**

Why this works (the mechanics)

Three invisibility sources on one subclass, and Rat King is one of them. Vermin (kill→reload), Vanishing Step (dodge), Stylish (debuffed kill). They overlap so you're invisible nearly continuously — and every Vermin trigger is a catalyst heal, so the uptime is also your health bar.
Vanishing Step double-dips the reload. Dodging reloads the weapon and makes you invisible — so a dodge simultaneously re-arms Vermin (full mag) and grants invis without needing a kill. Gambler's Dodge near enemies also refunds melee for another Snare Bomb.
Graviton Forfeit converts uptime into an ability economy. While invisible, grenade/melee/class regen faster, and invis duration is extended (stacking with Echo of Persistence). Because you're invisible most of the fight, your abilities are effectively on a permanent discount, and at max invis stacks you get a free Void Overshield on top of the catalyst's per-vanish heal.
The catalyst is the survivability — no Devour required, but you get it anyway. Infestation heals on every Vermin invis trigger. Layer Echo of Starvation's Devour (fed by Harvest's orbs/breaches off weakened kills) and you have two independent heal engines plus the Graviton overshield. This is why it solos add-dense rooms a fragile Kinetic primary has no business surviving.
Weaken is the connective tissue. Snare Bomb and Vortex+Undermining apply it; Stylish converts a weakened kill into invis; Harvest converts it into orbs + breaches; Starvation converts those into Devour. One debuff feeds the invis loop, the heal loop, and the ability loop at once.

Stats & mods

Class ~130 → Health 100+ → Weapons. Class regen re-arms Gambler's (the dodge that re-loads Vermin and re-grants invis); Health for the floor under the two heal layers; Weapons for primary damage since Rat King is your add-clear. Grenade/Melee can sit moderate — Graviton's invis regen and Gambler's refund cover ability uptime cheaply.

Mods: Sidearm Loader + Sidearm Scavenger (keep Vermin fed — fast reloads and reserves are the whole loop), Kinetic/Sidearm surge isn't a thing per-element the way energy surges are — slot Heavy Ammo Finder/Scavenger for the heavy and Void Weapon Surge ×2 on boots for your Void Special. Helmet: Harmonic Siphon (weapon kills → Orbs, feeding Harvest/Starvation). Class item: Powerful Attraction (dodge vacuums orbs → instant Devour/ability top-up) + Reaper.

Where it shines

Solo and master/legend add-clear: continuous invis + per-vanish heal makes Rat King a survivability primary, not a glass-cannon one. You clear rooms translucent and never stop healing.
Fireteam Rat King squads: if 2–6 allies also equip it, Rat Pack ramps the damage hard — niche but devastating in coordinated groups. Build doesn't depend on it; it's pure upside.
Champion coverage — flag: as a Kinetic primary sidearm, Rat King carries no reliable intrinsic champion stun in this build (see Verify notes). Deadfall's tether suppresses (covers Overload behaviour and locks down elites), Snare Bomb's weaken thins champion health, and your Void Special / Heavy archetypes must carry Barrier/Unstoppable stuns. Do not bring this expecting the sidearm to break champions.

Verify notes

Manifest confirms (hash 2362471601): Sidearm, Kinetic damage, 300 RPM, intrinsic Rat Pack + weapon perk Vermin. Vermin text (hash 861489047): "Reloading immediately after a kill grants a brief period of invisibility." Catalyst Infestation (catalysts.md): "Improved aim assist and recoil direction. Refreshes health on Vermin invisibility trigger." Exotic perk (exotics.md): Rat Pack stacks ×6 with nearby allied Rat Kings.
Champion stun is UNCONFIRMED. The Rat Pack intrinsic socket lists an empty `[Shield-Piercing] Barrier` line in the manifest with no associated text — this looks like a placeholder/leftover plug, not a verified bespoke stun, so the build treats Rat King as having no champion stun and routes champions through Deadfall's suppress + the secondary/heavy archetypes. If in-game testing shows Rat King actually pierces Barrier shields, that's bonus coverage; do not rely on it. Confirm against live game before counting it.
Vermin invis duration, catalyst heal amount, and Rat Pack per-stack damage % are not given as numbers by the encyclopedia — the manifest records behaviour, not magnitudes. Confirm in-game.
All armour/aspects/fragments verified against `docs/encyclopedia/`: Graviton Forfeit (Vanishing Shadow), exotics.md L29; Vanishing Step, Stylish Executioner, aspects.md L195/L153; Echo of Persistence/Obscurity/Starvation/ Harvest, fragments.md L18/L17/L22/L14. No fallback to `docs/knowledge/` was needed.
Rat Pack damage scaling only matters in a fireteam of Rat Kings — solo it's a flat baseline. Build is designed to be complete without the stack; the stack is upside only.

Mod selection (masterworked — full allocation)

Piece	Mod · cost	What it does
Helmet (3/10)	Heavy Ammo Finder 1e	Increases the effect of all contributions towards the Heavy ammo meter.
	Harmonic Siphon 1e	Rapid Arc weapon final blows create an Orb of Power. Rapid Solar weapon final blows create an Orb of Power. Rapid Stasis weapon final blows create an Orb of Power. Rapid Void weapon final blows create an Orb of Power. Rapid Strand weapon final blows create Orbs of Power.
	Harmonic Siphon 1e	Rapid Arc weapon final blows create an Orb of Power. Rapid Solar weapon final blows create an Orb of Power. Rapid Stasis weapon final blows create an Orb of Power. Rapid Void weapon final blows create an Orb of Power. Rapid Strand weapon final blows create Orbs of Power.
Arms (6/10)	Utility Kickstart 3e fill	When your class ability energy is fully expended, your Armor Charge is consumed and you gain class ability energy for each Armor Charge used.
	Momentum Transfer 2e fill	Causing damage with a grenade reduces your melee cooldown.
	Fastball 1e fill	Increases grenade throw distance.
Chest (7/10)	Ammo Reserves 3e
	Void Resistance 1e fill	Reduces incoming Void damage from combatants.
	Concussive Dampener 3e fill	Reduces incoming area-of-effect damage from combatants.
Legs (7/10)	Void Scavenger 1e	Void weapons get bonus reserves when picking up ammo used by that weapon.
	Void Weapon Surge 3e	Your Void weapons gain a small bonus to damage while you have any Armor Charge. Your Armor Charge now decays over time.
	Void Weapon Surge 3e	Your Void weapons gain a small bonus to damage while you have any Armor Charge. Your Armor Charge now decays over time.
Class Item (4/10)	Reaper 1e	Shortly after using your class ability, your next weapon final blow spawns an Orb of Power.
	Powerful Attraction 2e	Automatically collects nearby Orbs of Power when you activate your class ability.
	Bomber 1e fill	Reduces grenade cooldown when using your class ability.

All 15 sockets used, 10 energy per masterworked piece; costs from the manifest. Core mods are the build's engine; fill mods are strong defaults — swap freely (chest resists should match the activity's damage types).