My universe: species and concepts

Species: Immortals

Immortals:
They are the second specie that inhabits the chaos although they are aswell capable to invade realities like their nemesis the archetypes.
Immortals are significantly less numerous than archetypes (about 1 immortal for a trillion archetypes). They do have genders but are incapable of reproduction.
For appearances, they look like strange humanoids, with often an exposed brain and a heavily weaponized body. They can fuse and assimilate with their environment in order to create biomechanical weapons and armor directly integrated into their bodies.
Their sole purpose is to kill archetypes. All immortals are programmed with an insatiable hatred and lust for destruction towards archetypes and they will do whatever it takes to kill as many as they can, even killing themselves if necessary.
On the topic of death, as the name implies immortals cannot be killed. If their physical shell came to die, they will return to an ethereal but still conscious form , evolving and growing until they are strong enough to reincarnate themselves. Some pushback their reincarnation for several millennia all in order to gather more power. A reincarnation process is extremely destructive and leads to the annihilation and assimilation of all life and mater in a determined radius. All mater in the destruction radius will be transformed and will serve to compose the immortal's body.
Immortals that have invaded a reality will reincarnate in a new universe each time, their ethereal form existing temporarily in the void, the conduent that unifies all universes.
Another important note, despite their many deaths, immortals always conserve the memories of their past lives.
They do become stronger with each reincarnation but they slowly loose more and more of their morals and emotions.

Major immortals that I have drawn : Talos, Abad0n Pr1me, Nosfera, Abaddon imperior (incoming )

Abad0n Pr1me :
Biomechanical immortal
Status : deceased, has reverted back to his ethereal form, although something is wrong...
Alliances: none, but did assist the order of the knights of the cosmos multiple times

Talos:
Biological immortal
Status : dormant
Alliances: none

Nosfera :
Biological immortal
Status: active, curently governing over all banished demons from hell aswell as other demonic creatures
Alliances: the second demonic empire (which she founded)

Abaddon imperior :
Mechanical immortal
Status : active, crowned as the fifth knight of the Cosmos
Alliances : member of the knights of the cosmos