Iron Marines+ Boss Guide: How to Defeat Void Prowler and Aart Ruin

To defeat major campaign bosses in Iron Marines+, draw targeted frontal attacks away from your squads using a mobile hero, clear summoned minions before refocusing the boss, and swap squad types to counter armor and shielding mechanics. Bosses have deep health pools and immunity to crowd control such as stuns and knockbacks, making arena positioning and target priority your main tools for survival.

General Boss Tactics and Squad Control

Boss encounters test your spatial management under heavy fire. Managing threat and preserving squad headcounts ensures your damage output remains steady throughout multi-phase battles.

Anchor aggro with your hero: Position a durable hero opposite your primary firing line to force the boss to face away from fragile units. This directs telegraphed red conical or rectangular attacks toward map edges rather than through your army.
Isolate summoned reinforcements: When adds appear, pull ranged squads back just far enough to break melee contact, then burn down the secondary targets using splash or anti-infantry skills. Do not attack the boss while adds remain alive.
Preserve squad continuity: If a squad takes heavy casualties, pull the surviving unit back to the arena perimeter to reinforce. Reinforcing an existing squad preserves command points compared to paying the full redeployment cost after a squad wipe.

How to Beat the Void Prowler

The Void Prowler relies on stealth, sudden repositioning, and burst melee strikes that punish tightly clumped units.

Void Prowler Pattern:
Stealth Cloak -> Targeted Leap -> Ground Tremor -> Add Spawn

Evading Stealth and Leap Attacks

When the Void Prowler cloaks, it breaks your targeting lock and prepares a leaping strike on vulnerable units:

Spread your squads outward immediately to avoid stacked impact damage from the leap.
Keep your hero moving near the center to intercept the boss the moment it lands.
Keep fragile long-range units out of narrow choke points where retreat paths can be blocked.

Clearing Adds and Tremors

After landing, the boss triggers a radial shockwave that slows nearby troops and summons burrowing void adds. Immediately redirect all squad fire onto the adds. These creatures deal rapid chip damage and pin units in place, leaving them exposed to follow-up boss strikes. Resume firing on the Void Prowler only after the arena floor is clear of adds.

Unit Selection

Deploy mobile mid-range squads rather than slow, heavy artillery. Artillery units struggle to track targets that leap rapidly across the screen, leading to missed volleys and lost damage.

How to Beat the Aart Ruin

The Aart Ruin is a fortified mechanical construct that uses energy barriers, auxiliary turrets, and creeping artillery zones. Defeating it requires swapping to armor-piercing damage and methodically disabling defensive subsystems.

Phase	Boss Behavior	Primary Hazard	Priority Action
Phase 1: Activation	Stationary cannon fire and frontal lasers	Heavy directional blast down the center lane	Flank the structure and attack from the sides
Phase 2: Barrier Protocol	Kinetic shield activates, granting invulnerability	Sub-turrets deploy around the perimeter	Destroy exterior sub-turrets to drop the shield
Phase 3: Overdrive	Fast-tracking artillery and ground barrages	Red carpet bombardment zones	Maintain constant movement while bursting the core

Breaking the Phase 2 Shield

Attacking the main chassis during Phase 2 deals no damage while the kinetic barrier remains active. Direct all units to destroy the perimeter sub-turrets immediately. Spend hero burst abilities on these nodes to drop the barrier quickly, as prolonged shield phases allow ambient artillery to wear down your army.

Unit Selection

Standard rifle infantry lack the armor penetration needed to damage the Aart Ruin effectively. Deploy dedicated anti-armor squads or heavy energy weapons through dropship call-ins or base conversions to crack its defenses before bombardment overwhelms your position.