Lost soul (Doom Eternal)

The lost soul returns in Doom Eternal. It has not yet been seen to occur as an independent enemy, however; all instances seen so far have been spawned by the pain elemental. It is also unknown presently how the pain elemental's lost souls attack, as they have so far only been observed hovering above their "parent" monster and being thrown by it like living grenades.

Tactical Analysis
Lost Souls are unusually weak to the Ice Bomb, and will be instantly killed by it.

Lore
Lost Souls are derived from the Damned- the countless unfortunate mortals taken to Hell as slave labor. Those of the Damned who are no longer able to work are sent to vile pits where their souls are extracted for later use; the souls which escape after being extracted take a physical form as Lost Souls, being driven hopelessly insane in the process.

Haunted by fragmented memories of their old lives, they roam endlessly seeking something that can end their suffering.