Lost soul (Doom Eternal)

The lost soul returns as an enemy in Doom Eternal. It can either spawn as an independent enemy or be spawned by the pain elemental. Pain elementals can throw the lost souls spawned by them like grenades.

Tactical analysis
As was the case in the previous game, lost souls are suicide units. Normally they drift aimlessly, but when they see the player their flames turn from blue to red and they fly at full speed at the player before self-destructing. Lost souls spawned by a pain elemental will immediately enter their aggressive state and will charge as soon as they are spawned.

Lost souls are unusually weak to the Ice Bomb, and will be instantly killed instead of being frozen. The combat shotgun is also effective, and as an added bonus it knocks the lost soul flying backwards until it hits a wall or another monster, at which point it will explode and damage anything nearby.

Lore
Lost souls are derived from the damned - the countless unfortunate mortals taken to Hell and forced to perform slave labor for all eternity. Those of the damned who are no longer able to work due to maiming or dismemberment are sent to vile pits where their souls are extracted for later use; the damned souls who lucky enough to escape after being extracted take a physical form as lost souls, being driven hopelessly insane in the process.

Haunted by fragmented memories of their mortal lives, lost souls roam mindlessly throughout the Hellscape, seeking something that will end their suffering with a final death.