Iron Marines+ Elder Eggs Guide: How to Beat the Swarm Mission

To destroy the alien elder eggs and survive the insect horde in Iron Marines+, secure the surrounding Ether nodes, establish a durable frontline to hold incoming swarms, and burn each egg down with Pyronian flame attacks during the brief lulls between enemy waves.

Mission Objective and Target Priority

The primary objective requires destroying two heavily fortified elder eggs while repelling continuous insect swarms from adjacent underground nests. Attacking an egg without clearing nearby threats triggers fast melee hatchlings and armored burrowers that can quickly overwhelm isolated units.

1. Clear the Perimeter: Eliminate outer nests and acid-spitting bugs along the approach before engaging the egg chamber.
2. Anchor the Frontline: Station high-durability units outside the egg's aggro perimeter to intercept wave spawns at a choke point.
3. Burn Down the Egg: Once a swarm wave is eliminated, focus all single-target abilities and flame attacks directly on the egg sac before the next wave arrives.

Always destroy the egg closest to your drop zone first. Eliminating this target lowers overall hatchling density, freeing up resources and squad capacity to push deeper toward the second egg.

Recommended Squad Roles

Pyronian flame units excel against insect bio-armor and clumped hatchlings, while armored brawlers and long-range marksmen keep your formation stable.

Position an armored unit in front to absorb melee insect attacks. Place Pyronian flame specialists directly behind them to blanket both the incoming horde and the egg sac in persistent area damage. Keep at least one ranged marksman in reserve to pick off distant acid spitters before their corrosive projectiles melt your frontline.

Securing Ether Nodes and Defenses

Ether nodes near the nests provide the resources required to reinforce fallen squads. If you push toward an egg without securing these points, wandering insect patrols can recapture them and cut off your economic flow.

• Erect Turrets on Hardpoints: Build automated turrets on captured defense points flanking your main path to thin out wandering patrols.
• Pause Attacks During Waves: When the game alerts you to an incoming mass assault, stop attacking the egg immediately. Pull back behind your tank, eliminate the swarm, and resume damaging the objective only when the area is clear.

Handling Hazards and Egg Thresholds

The terrain around the elder eggs features environmental hazards and mid-fight spawn spikes that require active repositioning:

• Avoid Corrosive Slime: Slime puddles drain unit shields and reduce movement speed. Lure bugs onto clean ground before spending heavy combat cooldowns.
• Counter the 50% Health Trigger: Dropping an elder egg below 50% health triggers a burst of elite armored brood guards. Save hero active abilities and tactical strikes for this threshold to eliminate the guards the moment they surface.

Extraction After Egg Destruction

Destroying the second elder egg enrages the remaining hives, accelerating the enemy spawn rate. Do not remain in the nest area to hunt leftover bugs. Regroup all surviving units around your commander, use Pyronian fire to cover your rear against pursuing hatchlings, and march your armored units forward through the exit corridor to complete the mission.