Light, a former member of the Concord of the Tribes, is betrayed and left for dead. He escapes to the Abyss, a treacherous dungeon, where he uses his Unlimited Gacha skill to summon powerful allies, including Mei, a Level 9999 warrior. Over time, Light builds a kingdom in the dungeon, gathering a loyal following of powerful warriors. Now, he seeks revenge against those who betrayed him.