IS-0139

IS-0139 is a humanoid crystalline entity encountered in Abiotic Factor. It has several multi-jointed appendages sprouting from its back, and it is capable of camouflaging itself until it becomes almost completely transparent. When it reveals itself, its flesh is covered in violet and lavender crystal growths. In GATE records, it is described as an extremely evasive creature whose biology has been difficult to study because it can refract visible light to hide itself and may explode into shards under stress.

IS-0139 can be found patrolling or standing still while under camouflage, and it usually favors keeping its distance in combat with hit-and-run tactics. It is a fragile enemy overall, but its speed and invisibility make it hard to track without paying attention to its subtle reflections, movement cues, and distinct sounds. It can appear on the roof of the last passenger car at the end of The Train, and it can also show up during an Assault Event with no warning beyond the usual sound cue that something has spawned near your base. Its facility staff designation suggests it was identified only by its IS registry number before The Order’s attack, and its similarity to IS-0211 implies its symbiote may originate from Anteverse 17.

In combat, IS-0139 usually avoids fighting at close range unless forced, and when it attacks from range it briefly becomes fully visible while firing an energy bolt from its mouth. If a player gets too close, it may instead rush in with a lunging stab using its arms before fleeing again. It can resist bullets, so firearms are not the most efficient answer despite its low durability. Melee weapons can kill it quickly, but its unpredictable movement can drag out the encounter, so ranged weapons are generally the safest way to handle it once it has been located. If a frozen IS-0139 is struck or otherwise revealed, it exposes the position of a nearby hidden target.

When killed, IS-0139 falls onto its back as its camouflage fails, then explodes harmlessly into dust. It always drops Powdered Crystal.

• Use lights, especially flashlights or headlamps, to catch the reflections that betray its position.
• Listen for its movement and attack sounds when it is cloaked.
• Do not rely on firearms alone; it resists bullets.
• Melee is effective if you can keep up with its movement, but ranged weapons are usually more practical.