Knull was betrayed by the symbiotes because they became tainted by honorable, noble, and benevolent hosts. Marvel Database
The Imprisonment of Knull was an act of betrayal by the Symbiotes against their tyrannical king and creator, Knull, whom they imprisoned to his throne in an eternal sleep on Klyntar, preventing him from returning due to his dangerous nature of destroying planets and light.
What Makes Him Pure Evil? Chosen by the Celestials to help maintain the universe as the King in Black, he rejected this duty and sought to destroy it instead.
Knull possesses powers that are not bound by universal limitations. He controls symbiotes, manipulates primordial darkness, and has enough strength to defeat gods and even Celestials. Thus, in a battle outside the universe where the Stones hold power, Knull would almost certainly guarantee victory against Thanos.
Venom then picks up Knull, flies into the air, and punches through the Symbiote barrier surrounding Earth, where he uses the Uni-Power to vaporize Knull. As a result of Knull's death, Eddie Brock becomes the god of the Symbiotes now that they are free of Knull's control.
Knull and his creatures are after Eddie/Venom because together, they contain a codex that can unlock Knull from where the symbiotes have trapped him. This codex was created when Venom resurrected Eddie in a previous film; to destroy the codex (and keep the universe safe), either Venom or Eddie must die.
Johnson Emeka Knull is more powerful than cosmic cube. his more powerful than a celestial beings like Odin, Thor, etc.. He split apart a universe and make it multiverses by his will alone.
Knull nearly succeeded in doing so, but was defeated when the Silver Surfer expended the last of his Power Cosmic to conjure a star right in front of him, bathing him in stellar plasma and blasting him across the cosmos.
One-Above-All is the most powerful character in the Marvel Universe. Although they are not technically a superhero, but rather the supreme deity of the Marvel Multiverse, any discussion of powerful characters would be incomplete without mentioning One-Above-All!
Galactus's fear: The fear stems from the sheer cosmic power Franklin possesses and the potential for him to become a threat to the universe.
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Weaknesses. The Light: Knull is vulnerable to a metaphysical force he refers to as "the Light", which came into being with the Big Bang and was spread through the Abyss by the Celestials. The Light manifests as concepts such as honor, benevolence, and nobility; and physically as the divine power wielded by gods.
Riot is one of the five symbiotes forcibly spawned from Venom by the Life Foundation and is arguably the weakest of the group. Unlike its siblings, Riot does not possess any unique abilities or powers that separate it from the average symbiote.
His arrival is an apocalyptic event—heroes like the Avengers, X-Men, and even cosmic beings struggle to hold him back. It is Eddie Brock (Venom) who ultimately becomes Knull's greatest opponent, proving that even the darkest creations can rise against their maker.
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He was a primordial being of darkness who is the creator-god of the Symbiotes. Knull is one of the arch-enemies of Venom and his host, Eddie Brock.
Death and legacy
During the "King in Black" storyline, Sentry is summoned by the Avengers to fight Knull. He attempts to fly Knull into space, as he had done to Carnage, only for Knull to break free, kill Sentry by tearing him in half, and absorb the Void.
In Venom: The Last Dance, Eddie discovers that because Venom brought him back from the dead on a past misadventure, they'd forged a codex. That convenient MacGuffin works as a key that could unlock the merciless Knull, who once ruled over the symbiotes until they locked him up and ran away from his prison.
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As a result, Carnage is far more violent, powerful, and deadly than Venom. Kasady and the symbiote would then be the main antagonist in "Maximum Carnage" and Kasady would continually be the most recurring character to use the Carnage symbiote in many publications.
While Deadpool used to toy with the most powerful villains for fun, Death Grip is the one villain who truly scares him, as he has found something worth living for.
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