Lost soul (Doom 3)

The lost soul in Doom 3 is a head-sized flying demon consisting of a human face mounted on a flying rocket engine contraption. Its jaws are torn apart to allow it to open its mouth wider than a normal human could, and its teeth have mutated into long, pointy, needles.

Lost souls hover through the air at average speed, and attack by abruptly rocketing in a straight line toward the player at high speed and ramming into them, similar to the classic lost soul. Unlike the classic lost soul, however, Doom 3 lost souls can cover a larger area and can change course mid-charge. The lost soul is usually found in packs with other lost souls (which was often the case in the classic Doom games as well). Lost souls can be problematic opponents if the player does not manage to kill them quickly. They first appear in the EnPro facility.

The first appearance of a Lost Soul occurs in a grotesque cutscene with Theresa Chasar, one of the few female UAC employees stationed on Mars. When the marine approaches, she whispers, "help me," then her facial skin starts to shrivel inward while acquiring a horrible pale color. A lost soul then bursts out of her head, ripping out her spinal cord in the process.

Tactical analysis
Doom 3's version of the lost soul is very weak. It can be taken down by a single punch if necessary, or a couple of pistol bullets. However, they should not be underestimated as they are harder to hit due to their small size and fast speed. The lack of sufficient space to dodge their attacks also makes them more annoying compared to the classic version. It is best to use the machine gun or plasma gun to take down lost souls, due to these weapons' high accuracy and rapid rate of fire.

The Resurrection of Evil expansion pack replaced the lost soul with a new monster called the Forgotten One, which bears a closer resemblance to the classic version of this monster.