Demon God King

Demon King was an entity that was a member of the Evil Deities that rampaged across the New World two hundred years ago.

Personality
The Demon King is likely to be very ruthless and violent as he came very close to destroying the New World.

Background
The Demon King was an entity that participated in the Demon Gods’ Unrest bringing ruin across the New World. At some point in time, the Demon King had met his death at the hands of the Thirteen Heroes which vanquished him. To this day, it was still possible to see traces remaining from that battle in a certain place long ago.

The Lizard Man Heroes Arc
According to Zaryusu Shasha, he remembered the Demon King as someone who had led demons under his banner, and had almost exterminated the entire world in the process.

The Men in the Kingdom Arc
During her battle with Jaldabaoth, Evileye noted this demon's power and abilities to far exceed that of even the Demon King who she knew from the far-off past.

Abilities and Powers
The Demon King seems to possess authority in leading an army of demons against the New World's military forces.

Trivia

 * According to Ainz, Demiurge has set his long-term plan in motion which involves the creation and rise of the Demon King known as Jaldabaoth. Demiurge told Ainz that his intention was to place Jaldabaoth upon the throne of the Demon King.
 * Although a Demon King was not by any means that he is stronger than everything else, it was common sense in this world that having this as part of their name meant that it was the strongest of the demon race.
 * In the Web Novel, the Demon King had also met his end at the hands of the nine goddesses that descended from the Heavens rather than just the Thirteen Heroes alone.