Deimos is the lord of all Infested Marines. It is unclear how he came to possess such monstrous form. Physically he still vaguely resembles his infested soldiers, and bits of his armor can be seen through his twisted bulk. Deimos wields an Assault Rifle covered in mutation. He is a lumbering monstrosity that ignores all Armor mechanics including Kinetic Armor.
Deimos will spawn at a random point around the map. Lt. Sheng will suggest that the team chase him down before he reaches a variable destination. If he is not stopped before he reaches his destination, he can release several Titans, destroy all the Devastators, or cripple Ivax. When he says his dialogue, the fight will officially commence and he will begin spawning Minions.
Deimos is a particularly difficult boss to tank. His Minions, Shock, and ability to bypasses armor makes tanking ill advised. His attacks are fast, powerful, and will slow his target by 60%. Ivan, with his high health regeneration, can tank Deimos with some level of success. He will need the support of a Medic to keep him healed. Skills that distract, slow, or stun such as Mad Spark, and Force Push help when dealing with Deimos. A Psi-Ops can use Mental Projections to tank for a limited time. Technicians can also tank with limited effectiveness due to high health regeneration.
When fighting Deimos, avoid using the UA GPR-12. The M5 Pulse Rifle does very well, and the L3 Grenade Launcher, P-45 Gauss Pistol, XM814 Heavy Machine Gun also work. The MP9A2 SMG can be extremely effective with armor reductions such as Armor Piercing ammo, Laser Designator, and Motion Sensor. Without any reductions, the SMG performs decent because of Deimos's type class, but loses about half its damage from armor reduction.
Units hit by Deimos's Assault Rifle are shocked by its tremendous power. As a result, their movespeed is decreased by 60% for several seconds, making it difficult to escape.
Deimos is massively tall, and as a result he can easily see over walls and other sight obstructions. He shares this vision with the rest of the zombie horde. Never engage Deimos from short range on a ledge, the combination of Shock and Spotter will cause him to easily kill you before you can escape.
Deimos will bypass armor mechanics. Avoid his attacks whenever possible.
Deimos will periodically lay eggs. These eggs will hatch into Minions if not killed within seconds. Minions have a high base health, are fairly quick, and can charge on Nightmare Mode. Their melee attack is slower than a normal Zombie's but as strong as an Agron's. If not killed quickly enough, Minions will explode into Napalm Fire. Napalm Fire will burn anyone who touches it and anyone who comes close to them. It deals terrible damage over time and slows effected players by 40%. Without immediate healing, any burning players will almost surely die. On top of this, exploding minions will restore a large portion of Deimos's total health.