Adalman

A skeletal specter, originally one of Clayman's Five Fingers. In life, he was a practitioner of holy magic, but in Book 6, his misconceptions about holy magic were exploited by Shuna, leading to his defeat. He joined the Jura Tempest Federation along with his subordinate specters. Recommended by Shuna in Book 8, he initially oversaw the 60th floor as a floor guardian. Upon joining the federation, he regressed to a wight, but evolved back into a king of specters after absorbing a vast amount of magical essence from the labyrinth. In Book 14, Rimuru transferred a soul to him, allowing him to evolve into a mid-tier holy spirit of light, the Luminous Skeleton, and he was appointed as one of the Twelve Guardian Kings, earning the title of Gehenna Lord.

Adalman greatly respects Rimuru and Shuna with exaggerated attitudes and words, which Shuna finds overbearing, and Rimuru, though accustomed, feels uncomfortable around him. Having lost his holy magic due to weakening, in Book 10, Rimuru grants him the secret arts of faith and grace, restoring his power and holy magic by making Rimuru the object of his faith. In Book 12, his rapid growth from defeating Shinji and others earns him a promotion to the guardian of the 70th floor, and he also reunites with his lifelong friend Gadra.

With the skill "Holy Demon Reversal," created with Beretta's help and gifted by Luminous as an apology, he turns himself and his subordinates into holy beings, overcoming his weakness to holy magic. His awakening evolution enhances his control over the dead, including enemy soldiers, and strengthens his protection over them. He acquires the ultimate gift "Necronomicon," expanding the power of his army made up of numerous dead. See also "#Finger of Adalman."

Albert

Originally a spectral knight under Clayman. In life, he was a holy knight of the Western Holy Church and served as Adalman's guard, remaining loyal even in death. Upon joining the federation, he regressed to a skeleton swordsman but evolved into a Death Paladin after moving to the labyrinth, changing from a skeletal form to a young man's appearance. In Book 14, he receives a mythical spirit sword captured from the Eastern Empire from Rimuru, and with Adalman's awakening evolution, he evolves into a mid-tier holy spirit of fire, the Gehenna Paladin, and earns the title.

Like Adalman, Albert excessively respects Rimuru. He is a master swordsman who can match Hakurou in combat, and after acquiring "Holy Demon Reversal," he no longer has any weaknesses. He serves as the vanguard for Adalman on the 70th floor while also teaching swordsmanship to holy knights visiting the labyrinth for training. His awakening evolution grants him the ultimate gift "Immortal," entrusting his soul to Adalman, making him an immortal being as long as Adalman lives.

Wenti

A colossal spectral dragon at the pinnacle of undead creatures, who faced Adalman in life and ended in a mutual defeat, forming a master-servant relationship and becoming his pet. In Book 6, she disappears due to Adalman's defeat by Shuna, but is summoned back to the labyrinth by Adalman regaining his power in Book 10. In Book 14, named by Rimuru, she can transform into a beautiful woman clad in dark garments, and with Adalman's awakening evolution, she evolves into the Gehenna Dragon, earning the title of Infernal Dragon King.

Merely touching her eerie aura can destroy one's mind, and she emits a corrosive breath (Zombie Breath) that contaminates the minds of those affected, turning them into zombies under Adalman's command. Only direct attacks on her soul are effective, but with her awakening evolution, she acquires the ultimate gift "Eternal," entrusting her soul to Adalman like Albert, making her an undying existence as long as Adalman lives.