Aliens Dark Descent: How to repel a Massive Onslaught? Aliens Dark Descent guide, walkthrough

A Massive Onslaught is a difficult xenomorph attack in Aliens Dark Descent, in which marines can easily die. From the tips in our guide you will learn when massed attacks occur, how to prepare for defense and how to behave during the battle.

Last update: 21 June 2023

During the course of Aliens Dark Descent, there are a lot of battles to fight, and the most difficult of them are Massive Onslaughts. On this page of the guide, we show when to expect a massive assault, how to prepare for one, and how to lead your marines during these large battles.

• When may Massive Onslaught happen?
• Preparing a defense
• Leading your Marines during the battle
• ARC and Massive Onslaughts

When may Massive Onslaught happen?

A Massive Onslaught is a large-scale attack of the xenomorphs, with elite units being among them. Possible attack can be expected in-advance. In the top right part of the screen, you can see a bar called alien aggressiveness. When the bar fills past the red exclamation mark, expect an imminent attack.

When that happens, you'll receive a warning of an Onslaught incoming and a timer will appear. Use the time you have left to do following steps, as surviving such an attack is very difficult.

Preparing a defense

Here is a list of all the steps to be taken before the xenomorphs arrive:

1. The most important of the steps is quickly finding a good place to mount a defense. It is important to choose a location that has as little corridors leading to it as possible. The best choice would be a medium-sized room with only 1 entrance or a locked door at the end of a corridor.
2. Start with sending marines to weld all the doors leading to the room. This defensive measure won't last for long, but the xenomorphs still need to break through them which will slow their assault.

When it comes to defense itself, you have a choice of gadgets suited to such a task. These mainly include:

1. Sentry Gun - place it so it is pointed to a direction from which the monsters will appear from.
2. Mines - you can place them, for example, at the doors or other narrow bottlenecks.

Before the xenomorphs come knocking, check the current status of the unit. Make sure that the team has enough ammunition for their main weapons. If the current magazine is depleted, consider a pre-mature reload of a weapon even if it means losing some ammo.

Leading your Marines during the battle

After a Massive Onslaught begins, remember to:

1. Use active skills to slow down or to eliminate xenomorphs faster. One of the starting skills - Suppressive Fire - is very useful when facing a lot of enemies.
2. Focus on elite xenomorphs. These are the biggest threat and you should start weakening them as early as possible.
3. Prevent monsters from breaching your position. If the creatures get past your defense line, use an ability such as Shotgun Blast.
4. Help attacked marines. Focus fire on those monsters that pose the greatest threat to any of your marines, as they can be killed, gravely injured or kidnapped.

ARC and Massive Onslaughts

1. There is a way to avoid an Massive Onslaught, or limiting its level of difficulty. This involves a quick return to the ARC, and will unfortunately only work if your squad is at a relatively short distance from the vehicle.
2. Once the ARC is near, you can defend based on it (its cannon is a lot of firepower) or board the ARC and start traveling. The Marines are safe once in the vehicle and after reaching your destination, the attack should be over.