Eight Greed Kings

Eight Desire Kings (八欲王) were legendary figures in the New World. They appeared five hundred years ago and managed to conquer the world with incredible power before succumbing to infighting.

Background
Five hundred years earlier, the Eight Desire Kings appeared and sought to conquer the New World. During their world conquest, they met Surshana and successfully slew the player who, according to the Theocracy teachings, died trying to defend humanity from their reign.

According to some folk tellers, they exaggerated tales about the Eight Desire Kings, calling them beings who stole the power of the God and ruled this world using their absolute strength. Being taller than the sky with the likenesses of dragons, the Eight Desire Kings were capable of destroying numerous countries and dominant races and species in an instant. As a result, they wiped out most of the powerful races, like the Dragon Lords, paving way for humans to thrive and grow in strength. They were some of the few besides the Six Great Gods to spread Tier Magic further throughout the New World.

The rule of the Eight Desire Kings was surprisingly beneficial for humanity. The Eight Desire Kings treated the humans rather well, while demi-humans and heteromorphs were hunted. Even the ensuing power struggle, which resulted in the weakening of all races, provided an ample opportunity for humanity to flourish in the vacuum.

However, their greed ended up pitting them against one another and created a sour division among them. Ultimately, this resulted in their group's demise as they perished one by one. One could say that the Eight Desire Kings' desires ran deep, and they fought each other over their own possessions was what caused their mutual extinction. In the end, the Eight Desire Kings' rule, after conquering the world, was short-lived.

Nowadays, most of the things they've constructed were literally destroyed, leaving only ancient ruins that once made up their civilization. The only city left standing is under their floating castle, Eryuentiu. Such city was supposedly their country's capital built by the Eight Desire Kings once they have managed to conquer the new world.

After their downfall, Platinum Dragon Lord took up residence in the former Guild Base and took on the task of guarding their magic items to ensure no one would ever be able to misuse them. However, he did allow the members of the Thirteen Heroes to take some of the items to aid them in their battle against the Evil Deities.

The Undead King Arc
There were three magical items that were unimaginably powerful. One of these was left behind by the Eight Desire Kings who had conquered the New World in an instant five centuries ago.

The Men in the Kingdom Arc
Evileye brought up an exaggerated tale concerning the Eight Desire Kings while talking with both Climb and Gagaran about the group of players. She also talks about an extremely powerful item out of all the rest they have in their possession, which confirms the existence of 10th tier spells.

The Ruler of Conspiracy Arc
When the cardinals of the Slane Theocracy discussed if whether or not Ainz Ooal Gown could be Surshana, they shortly denied it thereafter. This is because according to their country's oral traditions, the God of Death was said to have been slain by the Eight Desire Kings.

Strength
The Eight Desire Kings were known to be immensely powerful, as they had slain most of the Dragon Lords in battle. They were also able to destroy numerous countries and went on to rule the world with their overwhelming strength, at least for a short while.

On the other hand, they happened to possess a countless number of powerful items in their arsenal, which gave them the means to conquer the New World. Among their items were the Eight Great Weapons, wielded by the kings, and their guild weapon known as Guilty Ordinance.

Among these items formerly in their possession, another one of them is mentioned by Evileye, who stated that their "Nameless Book of Spells" was worth the price of a single country. Given its value, it is possible it may be a World Item. Fluder Paradyne has also stated that if he had a magic item from the Eight Desire Kings, he was certain that his Magic skills would rise by another level.

In the Web Novel, they have unimaginable powers which could move mountains and part the seas. Platinum Dragon Lord claimed that the Eight Desire Kings perpetuated the contamination of the New World with Tier Magic. It has taken about a number of ten Dragon Lords to defeat one member of the Eight Desire Kings.

In other words, one Desire King alone would required a plurality of resources and manpower to be dealt with by the True Dragon Lords. To kill one Desire King however, came at a heavy cost as the dragon side must suffer ten times the damage each time until all eight of them are finally slain in battle.

Trivia

 * The Eight Desire Kings were the second group of YGGDRASIL players to be transported to the New World after the Six Great Gods and before the two players of the Thirteen Heroes.
 * In the Web Novel, it is certain that they are YGGDRASIL players, as their city produces items which only exist on Earth, like a suit or a katana, and they owned a guild weapon.
 * It is also confirmed that they can revive after death, though they become weaker and weaker after repeating the revival. This might be due to the revival penalty of YGGDRASIL.
 * It's stated that if the Eight Desire Kings had not attempted to dominate the world, humanity would have already been annihilated by the stronger races.
 * A fun fact found in the Web Novel is that the Eight Desire Kings were compriseed of seven males and one female.