Proving Grounds
Grandmaster Vanguard Alert · Cabal · Nessus

ProvingGrounds

A Season of the Chosen battleground, re-taught in modern Grandmaster Vanguard Alert language. Board the Imperial Land Tank Halphas Electus on the Nessus surface, manage champion frame coverage instead of old Artifact mods, and finish Ignovun, Chosen of Caiatl in the rear arena via the Rite of Proving — breaking his immunity shield each phase before the firebombs and Solar Seekers bury you.

Faction
CabalThe Chosen · Caiatl's Imperial Cabal
Combat range
MixedNessus surface into the Land Tank's bays
Champions
Weekly setTypes follow the weekly modifier set
Boss
IgnovunRite of Proving · immunity shields
Wipe risk
Vehicle BayTank blasts & reinforcement waves
00 · Read This First

What this run really is

Proving Grounds is a linear Cabal battleground fought almost entirely inside the Land Tank Halphas Electus — in a Grandmaster Alert its danger isn't the layout, it's the Vehicle Bay's Goliath Tank blasts on the way in and the immunity-shield reinforcement waves during Ignovun. Treat the bay as a positioning puzzle and the boss room as a shield-break race, not a pure DPS race.

The one-sentence identity

Fight up the Nessus battleground into the Land Tank, survive the Vehicle Bay and its Goliath Tanks, clear the champions the week's modifiers assign, then burn Ignovun through three phases — breaking his Rite of Proving immunity shield each time he leaps to the pedestal.

Everything you bring serves three jobs: survive the Vehicle Bay, cover the champion types present, and break shields then burst Ignovun between firebomb volleys. Build for those, not for the trash.

What old guides get wrong

  • They tell you to slot a seasonal anti-Champion Artifact mod. Stun is frame-intrinsic now — bring the right archetypes (weapon guide).
  • They quote a fixed champion list. GM champion types and counts follow the weekly modifier set.
  • They name a specific Adept reward. The chase is the weekly Tier 5 weapon, and it changes every reset.
  • They say you "board and disable the tank, then fight in the hangar." You never disable the tank — the whole strike is aboard it, and Ignovun is fought in a rear arena via the Rite of Proving, not a hangar.
01 · Champion Coverage

Cover the frames, not the mods

Anti-Champion is built into weapon frames now — there's no Artifact mod to forget. Bring archetypes that cover the types the week assigns. Champion types follow the weekly modifier set.

Most common here

Barrier

› Pierce / break the shield
Cabal Colossi wear the Barrier tag here. Bring a Barrier-intrinsic frame to strip the shield, then finish. Don't waste a Super into an unbroken shield — and don't let them regen behind cover.
Per weekly modifier set

Overload

› Disrupt to stop the heal
Champion types follow the weekly modifier set. If the launch screen lists Overload, an Overload frame interrupts and stops the heal.
Per weekly modifier set

Unstoppable

› Stagger before it charges
Unstoppable Incendiors rush and hit hard in the open and in the Vehicle Bay. An Unstoppable frame staggers them at range — stun, then delete before they close the gap onto your cover.
The modifier readout, every time: (1) enemy pressure — which champions, shields, and faction units; (2) weekly modifiers — surge, threat, banes, player stakes; (3) the single modifier most likely to wipe a casual team; (4) one build swap that answers it. Run that readout on the launch screen before every GM Alert. Champion types follow the weekly modifier set. The hub's modifier glossary explains Medusa, Focused Fire, and the rest.
02 · The Route

Onto the tank, top to bottom

Five beats: the Nessus battleground entry, the Land Tank exterior mini-boss, the Vehicle Bay, the power-core puzzle, and Ignovun's Rite of Proving arena. The strike is a straight line deeper into the tank — the skill is when to push and when to hold the dead zone. Here's the route at a glance; each beat below carries its own notes.

Full routeNessus surface → Halphas Electus rear arena
Proving Grounds full route A top-to-bottom route through five areas following the amber path: 1 Battleground Entry on the Nessus surface, 2 the Land Tank Exterior with a mini-boss that shields and calls reinforcements, 3 the Vehicle Bay tank room where Goliath Tanks and champions spawn in two waves — the hardest section, 4 the Power Core engine room with a deposit puzzle, and 5 Ignovun's rear arena where the Rite of Proving plate begins a three-phase boss fight with immunity shield generators. Champion spawn zones, the lethal Goliath Tank fire, and the boss immunity shields are marked. ▼ deeper 1 Surface · Nessus Battleground Entry Flank left through cover · thin the first Cabal wave early champ 2 Exterior · the tank Land Tank Exterior Mini-boss shields at half · calls reinforcements champ spawns 3 Interior · Vehicle Bay Vehicle Bay Two waves · Goliath Tanks + champions · hardest section tank fire 4 Interior · engine room Power Core Collect cores · deposit while surviving waves deposit nodes 5 Boss · rear arena Ignovun · Rite of Proving Three phases · break immunity shields · dodge firebombs immunity shields
Route · push line Champion spawn Cover / nodes Lethal tank fire Boss
1
Beat · Battleground Entry

The Nessus Surface

"Flank left to the tank without spending your tokens."
The loop
  1. Spawn on the Nessus battleground and push toward the Land Tank, clearing the opening Cabal wave.
  2. Flank left through the cover near the spawn gate — it gives the cleanest line to the tank without crossing the open killbox.
  3. Watch for an early champion (or two) in the opening. Clear it with the matching frame coverage before pushing on.
PaceThis beat is forgiving on Normal and lethal on GM only if you sprint blind. Move as a group, cover-to-cover; a hero rush here burns a revive token you'll want in the Vehicle Bay.
ChampionCall the early champion type the moment it appears — strip or stagger with the right frame, then collapse together.
2
Beat · Land Tank Exterior

The Exterior Mini-Boss

"It shields at half and calls in friends before you can board."
The loop
  1. At the tank exterior the exterior mini-boss Valus Ozysas emerges and blocks the way onto the tank.
  2. At roughly half health he becomes immune and deploys a barrier — destroy the generator inside the dome to strip the shield, while he also calls reinforcements (including a champion) from the spawn gate.
  3. Clear the reinforcement wave and the champion before finishing the mini-boss, then board.
ChampionThe reinforcement wave usually carries a champion. Don't tunnel the mini-boss's health bar while a Barrier Colossus regenerates behind you — clear adds first.
PositionHold a piece of hard cover facing the spawn gate so reinforcements funnel into a kill lane instead of flanking you against the tank hull.
3
Beat · Vehicle Bay — hardest section

The Vehicle Bay

"Two waves, Goliath Tanks, and a one-shot if you stand in their line."
The loop
  1. Inside the Vehicle Bay, two waves spawn. Survive the first, then brace — the second is the spike.
  2. The second wave adds Goliath Tanks plus champions and dense adds. This is the widely cited hardest section of the strike.
  3. Kill Goliath Tanks by shooting the engine weak spots on their sides — not the front armor.
  4. Shelter in the bottom-middle dead zone to break the tanks' line of fire while you whittle them and the champions down.
Tank fireGoliath Tank projectiles can one-shot you in GM. Never sit in their firing line — use the dead zone and pillars, peek to hit the side engines, drop back.
ChampionChampions ride in with the second wave. Focus-fire them down together — a Barrier Colossus left alone will regenerate and reset your progress.
AmmoThis is the most demanding fight before the boss. Spend Heavy on the Goliath Tanks here if you must, but agree who picks up bricks so you're topped for the next stretch.
4
Beat · Power Core / Engine Room

The Power Core Puzzle

"Carry the cores, hold the deposits, survive the waves."
The loop
  1. Enter the engine room. This is a puzzle encounter: collect power orbs / cores dropped around the space.
  2. Deposit them into the devices to charge progress and open the way deeper into the tank.
  3. Survive the enemy waves between deposits — assign a carrier and a cover team so the deposit never gets interrupted.
CarrierWhoever holds a core is the priority target. Escort the carrier to the deposit and don't let them solo a lane full of Legionaries.
ResetThis is the last calmer stretch before Ignovun. Top up Special and Heavy, regroup your supers, and agree on opening positions for the boss arena.
5
Boss · Rear Arena

Ignovun, via the Rite of Proving

"Three phases — break the shield, dodge the firebombs, repeat."
The loop
  1. In the rear arena, activate the Rite of Proving plate. It charges supers and triggers a firebomb volley — be ready to move the instant you step on.
  2. Damage Ignovun. At roughly two-thirds health he leaps to the pedestal at the back, becomes immune, and deploys a barrier / shield generator while summoning reinforcements — champions on the first immunity wave in the GM.
  3. Destroy the shield generator mechanism to strip his immunity, then clear the reinforcements before resuming damage.
  4. Resume DPS. At roughly one-third health he repeats the leap, immunity, and shield generator — break it again.
  5. Throughout, he hurls tracking firebomb volleys and periodically floats up to summon Solar Seekers. Shoot both down — they overwhelm players who ignore them.
  6. The arena floor shifts barriers / pillars between phases. Re-read your cover each phase before committing to a damage spot.
ShieldsYou cannot rush his health bar. Each immunity phase gates damage behind the shield generator — assign who breaks it so the team isn't all shooting an immune boss.
FirebombsThe tracking firebomb volleys and Solar Seekers are the silent killers, especially right after you activate the Rite plate. Keep one player watching the air and shooting projectiles down.
ReinforcementsThe first immunity wave summons champions in the GM. Don't get collapsed on in cramped positioning — break the shield fast, then thin the wave from cover.
Map · Ignovun's ArenaBoss · Rear Arena
Ignovun rear-arena map A rectangular rear arena inside the Land Tank. The Rite of Proving activation plate sits at the front; stepping on it charges supers and triggers a firebomb volley. Ignovun fights from the open floor and, at roughly two-thirds and one-third health, leaps to a pedestal at the back where he becomes immune and deploys a shield generator while summoning reinforcements including champions. Players must destroy the shield generator to strip immunity. Barriers and pillars shift between phases, and tracking firebombs plus Solar Seekers can be shot down. Rite plate ⚡ charges supers · triggers firebomb volley barriers / pillars shift between phases Ignovun burst between firebomb volleys pedestal · immune + shield generator champ wave champ wave ⚠ break the shield generator to strip immunity · shoot down firebombs & Solar Seekers
Pedestal / immunity Cover / pillars Champion / reinforcement Rite plate Boss
03 · Loadout by Role

Bring four jobs, not four guns

A GM team is happiest when each player owns a job. Full build cards live in the class guides and the Prismatic deep dive — these are the jobs to fill and the archetypes that fill them. Names rotate with the meta; the jobs don't.

Anchor / Control

Room control + self-sustain

Hold the dead zone and keep the team topped through tank fire and add waves.

  • Warlock — Void Devour or the Prismatic Getaway loop.
  • Titan — Strand Banner of War for team woven mail.
  • A reliable add-clear Primary that respects the surge.

Champion Lock

Frame coverage

Carry the intrinsic stuns the week assigns.

  • Barrier + Unstoppable frames as the baseline here.
  • Add an Overload frame only if the week lists it.
  • See the weapon guide for which archetypes carry each stun.

Boss Burst

Damage between firebomb volleys

Burst windows beat sustained DPS — damage is gated by his immunity phases.

  • Hunter — Nighthawk Golden Gun for a clean single-shot nuke.
  • Titan — Thundercrash as a burst swap.
  • A heavy you can fire-and-reposition (rocket / LFR).

Emergency Support

Safe revive / shield break

The insurance that saves a token and strips immunity fast.

  • Hunter — Void invis (Gyrfalcon / Omnioculus) for safe rezzes.
  • A healing or overshield tool for the boss room.
  • A debuff (Tractor / Div) to speed the Ignovun phases.
Loadout note: these are the mid-2026 (Monument-era) jobs and archetypes — match the weekly surge when you pick your elements. For full, current builds, the class pages go deeper than any single route guide.
04 · Modifier Adjustment

What changes when the modifiers do

The route is evergreen, but the week's modifiers decide how you play it. The most common GM swings and the one adjustment each one asks for:

Medusa

Looking at affected enemies stacks Stasis slow toward a freeze. Deadly in the open Vehicle Bay — peek-and-cover from the dead zone and never hard-scope a Goliath Tank you can't disengage from.

No Radar / Blackout

You lose your spawn warnings and melees hit harder. Clear corners before committing, hold the bay's cover, and call reinforcement spawns by voice during the boss immunity waves.

Focused Fire

Heightened incoming damage. Tighten cover discipline everywhere and shorten your exposure windows — the Goliath Tank blasts and Ignovun's firebombs are twice as punishing under it.

Harsh threat / surge

Slot the matching resist mod for the threat element and match your DPS element to the surge on Ignovun. A mismatched surge can double your phase count and your shield-break windows.

Read the live set: this card lists the common swings — the launch screen shows the week's exact champions, banes, surge, threat, and player stakes.
05 · Common Wipes

Why teams actually lose this

Almost none of it is Ignovun's health bar. Proving Grounds wipes groups in four predictable ways — kill these habits and the run is yours.

1

Eating a Goliath Tank blast

The Vehicle Bay is the hardest section and the Goliath Tanks' projectiles can one-shot you in GM. Shelter in the bottom-middle dead zone, never sit in their line of fire, and hit the side engine weak spots.

2

Letting Barriers heal

A Barrier Colossus you don't focus down regenerates its health and resets the fight. Strip the shield and burst it together — never half-commit and let it duck behind cover.

3

Ignoring firebombs & Seekers

Ignovun's tracking firebomb volleys and Solar Seekers overwhelm teams who don't shoot them down — especially during the Rite of Proving activation. Keep one player watching the air.

4

Getting collapsed on

Reinforcement waves (extra champions / adds) spawn when the boss or mini-bosses raise their immunity shields. In cramped positioning they bury you — break the shield fast and thin the wave from cover before resuming damage.

The reward: when Proving Grounds is the active Grandmaster Alert, a Grade B or better clear awards the week's featured weapon at Tier 5 (first clear pre-masterworked with its origin trait). The weapon is the weekly chase shown in the Director. See the hub reward ladder.
Free guides · made by ThePsychDr

These guides stay free.

No paywall, no login. If a guide saved you a wipe, the videos and the people who watch them are what keep this site going.

Watch on YouTubeAll ways to support