Knull

According to Marvel continuity, Knull existed in the 'endless void' that preceded the seventh iteration of the cosmos. He crafted the primordial weapon All-Black the Necrosword and subsequently forged and propagated the symbiote species. When the Celestials arrived to seed the new universe, their light 'despoiled his kingdom of darkness'; Knull attacked the emerging cosmos, once even decapitating a Celestial with All-Black. In later history the symbiotes rebelled against him, binding and imprisoning Knull within an artificial planet called Klyntar ('cage' in their language). In modern-era events he escapes or is resurrected and wages the 'King in Black' campaign that surrounds Earth with a symbiote sphere and assaults its defenders, only to be opposed by combined heroic and cosmic forces including the Enigma Force (the Uni-Power).

Depictions in the source material consistently show Knull clad in black armor and associated with an eldritch darkness motif; he is visually linked to a black sword (All-Black) and to manifestations of symbiote armor. Sources note occasions when his armor is torn away in combat, but detailed canonical descriptions of his bare physiology beneath the armor are not provided in the supplied materials.

Knull generates and manipulates an eldritch darkness which he can manifest as weapons and living creatures (the symbiotes, including large dragon-like forms). He forged All-Black the Necrosword and used it to slay a Celestial. He possesses superhuman strength, durability, and apparent immortality, and can create, forge, and command symbiotes. Narratively he has slain gods and waged war at cosmic scale; he was bound by the symbiotes into Klyntar, later returned to lead an invasion of Earth, and in storyline incidents he has been shown to kill and absorb other entities' aspects (for example killing Sentry and assimilating the Void in those accounts). The Enigma Force is presented in the narrative as an explicit counterpower capable of defeating him.