CARNAGE is capable of fighting hundreds of thousands of Origin gods and billions of angels and their gods at the same without losing immediately. It is even gradually shifting the tides of victory in its favor. That is not something a demon king can do.
A demon king needs an army and maybe some allies to invade a plane. The invasion will also last numerous years. Victory and defeat won't be determined until after numerous clashes. One side will give up eventually. It could either be the gods or the demon king if they fail to maintain their strength.
A demon God on the other hand can take on a plane on its own. It is almost always a losing fight for the plane if a demon God comes prepared to take on a plane. A demon God becomes highly terrifying when they become world-enders.
World gods fear world enders so much that they don't want to come across the slightest traces of one or fight one at all. It is because the fight will not end until one of them is subsumed and overwritten. Every encounter with a world ender is a death match. There is no negotiation or truce. Death is the only result of every interaction with them.
You can't get rid of a World ender once it comes in contact with you. There's nothing that can prevent a fight with that world-ender. And that fight is a fight to the death. The fight is eternal until one of them dies. World enders have the persistence of chaos energy. They will continue to remain a threat that will follow you everywhere no matter how well you try to hide.
Demon gods don't have the power or virulence of world-enders. But that's alright. They are not fighting world gods. What they have right now is more than enough to roam the realm with impunity. They can even take on an entire plane with a single clone.
A world god when asked about the chances of the Lumen plane said, "You might be stronger than demon gods and world-enders, but all they need is a little weakness. A little opening in your defense and they will take root forever and continue to spread without end."
But the Lumen plane tried its best. They didn't give up without a fight. This is a matter of life and death to them after all. They won't just throw the towel in because a world god said there is no way to defeat a demon god. They fought back and were able to stop CARNAGE from entering the mortal realm.
Their defense is admirable. Those on the path of perfection and divinity set aside their differences and worked together in the face of this unprecedented calamity. Origin gods held the demon god's attention so it couldn't focus all its strength on the gods and bypass their defenses. And the gods did a splendid job in holding back the blood clones. But a weakness appeared.
A house might be so secure that it is impossible to break into. But forceful breaking and entering is not the only way to gain access to the house. You can use a key that you stole or someone from the inside can open the door for you. The demon God went with the second option. A weakness appeared from within the plane itself.
Demons are very good with deals. Their society needs deals and oaths to keep itself together or it will crumble. They need binding oaths to work together because they are all treacherous. They don't trust each other. Deals and oaths keep their society functioning.
Demon nobles can form a house because of the oaths of allegiance. The heads of the family can share their power through this bond of allegiance. Demon gods take it further. They can create races through the oath of allegiance by sharing their power. If there is anything that anyone needs in life, odds are it is most likely the need for power.
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Within The Lumen Plane.
The sun was eclipsed by a red object. This red object remains at night even when the sun is absent. It stays in the sky and casts a red glow on the inhabitants of the plane. This makes the inhabitants become easily irritable. They became prone to anger and fits.
For some of the inhabitants, the effect of the red moon is that they hear strange whispers. The whispers come from everywhere, both outside the mind and from within the mind. These whispers drive most of them mad. But as for those that remain sane after hearing the whispers, they get an earful of promises of power. Some disregard these promises as crazy talk, but others don't.
A boy was being bullied. He needed strength to fight back against his oppressors. He was recently beaten. He just gained some new bruises and injuries so he hid under his bed. He is hiding from his mother and his sisters. He doesn't want them to see him. They might ridicule him or beat him again if they see him.
Their society is a matriarchal society. The females are higher on the hierarchy and are more privileged.
His mother and sisters abuse him both physically and emotionally. They call him hurtful words and beat him until he bleeds. He has both physical and mental scars to show for his years of abuse.
They aren't wrong though. He is weak. It is because he was born that way. The males in the society of dark elves are weaker than the females but he is weaker than normal. He is of lower status even among the males. This has made him the target of ridicule and jest from both sides.
He was sobbing silently under his bed when he heard the whispers again. He has been hearing them for a while. But the whispers rang more clearly in his head than ever before. It is as if he has suddenly become more attuned to the whispers. It is as if he has become more accepting of CARNAGE.