Keiha

Overview
The Hidden Boss of the 100th floor of the restructured Sherden Dungeon.

History
He outranked the Demon King in terms of strength, but he was rather impatient and brutal compared to the Demon King. He thought of a way to be resurrected in the human realm without sacrificing any of his real strength in order to bring judgement to humans, and it was by sacrificing the Demons so that he could transfer his real body to the human realm. But the Demon King realized his plan and interfered, which made the resurrection incomplete, so he ended up being tied to the dungeon as a penalty of bringing his full strength over, and God used Their power to seal him off.

Abilites
He has low intelligence, so he attacks while switching between his best spells, and these are all area damage with different attributes.

By utilizing his mana, he used two shield walls, and each of them not only completely defended him from physical and magical attacks but also deflected them.

Trivia

 * Though he is not part of the Ten Demons, his power surpasses them.