The power of a demon Lord is not a small thing. A single demon nobles gets to bind the energy well to themselves and become the demon lord. So she is clearly special, but it is not enough for Beelta the demoness of gluttony.
If one can see into the center of the pillar that represents the energy well, one will see a round grotesque ball of flesh about 110m in diameter. As large as the ball is, it is very small when compared to the 1km diameter of the pillar it is in and when compared with the real diameter of the pillar, then the ball might as well be nothing.
The pillar possesses a lot more space within it than it shows from the outside of it. This ball is the demon lord of the plane and has the special perk of being able to live in the pillar. She had thought she was very big before she began living in it, but she has come to realize that she might as well be a speck of dust in the abyss.
That's the thing about getting wiser and growing stronger, you begin to realize how insignificant you are in the broad scheme of things. But what could be more important than a demon Lord? She knows what the answer to that question is. What she doesn't know is if demon kings are significant in the grand scheme of things. After all, you would expect demon lords, rare as they are, to be significant or special.
There can only be one demon lord in each plane of the abyss. There are less than a thousand of them in all of the high heaven realm. A demon Lord is as powerful as a grand god and a titan of law. If you crunch the numbers, that means that a single main plane in the realm has more titans of law than demon lords and there are more than 100,000 such planes in the realm of high heaven.
A single pantheon may have a lesser number of grand gods than demon lords but all the pantheons in the high heaven realm have more than ten thousand grand gods. All in all, demon lords are rare, but they aren't special.
Beelta would like to know why that is and if a demon king is significant, but she can't. She got this big by eating and accumulating power but she can't grow more than this. She has reached her limit. The worst part is that all this power will mean nothing in the face of the authority of a demon king. So she craved that power so much, but she can't have it.
Ever heard about the seven deadly sins? Demons of pride don't have weaknesses, demons of lust have very powerful magical abilities, and demons of wrath have strength and resistance above what other demons are capable of.
These are the seven most powerful sins but they weren't so powerful like so in the past. The change is because they have been embodied into a law of the world. In demon terms, the seat of the demon god of those seven sins has been occupied. The existence of a demon god representing the sins has elevated their power.
There aren't only seven demon gods in the abyss but they are the most popular ones. There is a demon god of gluttony and it makes the sin of gluttony very powerful. What this means for Beelta is that she cannot become a demon king of gluttony.
There can be many demon kings for a sin, but once a demon god is created, all the other kings will be demoted to demon lords and have their authority forcefully stripped. The existence of a demon god means demons with that particular sin are more powerful and they survive more, but they can't go past the stage of a demon lord.
This is why Beelta is stuck. The only way to become a demon king is to be bestowed the authority of one by a demon god. But why would an all-powerful being share his power with a lesser being? We are also talking about selfish demons here. Selfishness is a virtue for demons.
Take her situation for example. She has long broken through to the next rank as a demon lord. Her energy has reached the half-divine rank, so she doesn't need the enhancement of the energy well but she refused to leave for someone else to have their turn. Her selfishness is preventing more demon lords from being created just like the selfishness of demon gods is stopping demon kings from being created.
So that path is hopeless for her. It has happened before to some other demon lords but they were the vassals of the demon god before he ascended. Beelta isn't so lucky. She had grown stronger ever since she became a demon lord. Her unified energy has even upgraded to the half-divine rank a step above extreme but she can't take the trial of the abyss for the authority of gluttony anymore.
Imagine her shock when she sensed Aeternus the weird demon with access to chaos. Other demons got a longing for him as soon as they saw him. They knew instinctively that he was special but they didn't know why. Beelta knew why immediately.
The chaos that Aeternus has access to can warp her sin and make it Chaotic Gluttony instead. With that, she will be able to take the trial of the abyss for the authority of chaos or something. Aeternus represents her chance to break her limits and maybe find out if demon kings are significant in the world when she becomes one.
Even if she didn't have that knowledge, she would have tried everything to eat Aeternus. You can't dangle something good and create a feeling of longing for it within a demon of gluttony, one that ate her way to power and expect her to hold herself back from trying to take a bite.