Tenma, for as long as he can remember, has fought countless Demons, and along the way, enslaved them using Demon Subordination Magic, either choosing to do so because they may be useful in his goal, or due to being unable to kill a Demon, and thus being forced to capture it instead. The exact number of Demons he has enslaved is unknown, but Tenma has said that it is well below 100.
Formless Chaos, SethThe Formless Chaos, Seth (無形乱セス, Muyōran, Sesu) is a shadow demon, said to have no physical form, due to his Curse. His appearance takes the form of a shadowy apparaition, with wolf-like characteristics, including claws, and face, and has two distinct red eyes.
He is a fearsome Demon, but lacks any true physical greatness that is considered "impressive" among Demons, but still above Humans. However, his greatest strength is his magic, Eibito.
- Eibito (影人, Shadow People): Seth's magic allows him to manipulate "shadows", including himself. He compares his own body to that of a shadow, having no physical form when the maguc is activated, and is naturally weak to light-based attacks, but suffers no ill from the sunlight. The magic can be compared to Shadow Magic in a sense. However, unlike Shadow Magic, Eibito can manipulate the shadows of individuals, even without coming into contact with them, and turn Seth in an intangible mass of darkness. Seth can also "possess" people, by first possessing their shadows, taking controlling of a human body as a host. There is no real time limit to how long he can stay in a human body, but while he is, he cannot use Eibito's full power, and only manipulate his own shadow. Seth has also shown the ability to control people, in a form similar to "puppetry", by controlling the shadows of people, he can control a person's every movement, telepathically, and with hand gestures if needed, and can do so to a number of people, but doing so requires a shadow to be present, as well as the target being weak willed to allow him to control them.
Eternal Serpent, OuroborosThe Eternal Serpent, Ouroboros (限りない蛇ウロボロス, Kagirinai Hebi, Uroborosu) a female Demon with the lower body of a snake, and the upper form of a woman, complete with light purple skin, with tattoos on half her body, and elongated horns, with long white hair, that reaches below her waist, decorated with flowers. She also wears a rather revealing attire, revealing a large portion of her bust, and a small skirt on her waist.
Ouroboros is a very fast and agile Demon, her snake tail is also one big mass of muscles, allowing her to capture and crush people with ease, much like an actual snake does to its prey. However, she is more of a strategist than an actual combatant, exploiting her opponents weaknesses, and coming up with plans in order to better defeat them, which is the reason for why Tenma captured her, seeing her intellect as a valuable asset in Demon hunting.
Goddess of the Slave Planet, KyoukaSlave Star Angel, Kyouka (隷星天キョウカ, Reiseiten Kyōka)
Hand of Ruination JackalHand of Ruination, Jackal (手の廃滅ジャッカル, Te no Haimetsu Jakkaru)
Demonic Blade, EzelDemonic Blade, Ezel (魔剣エゼル, Maken Ezeru)
Immortal Calamity, TempesterThe Immortal Calamity, Tempester (不死厄災テンペスター, Fushi Yakusai, Tenpesutā) is one of the Etherious of the Dark Guild Tartarus that were enslaved by Tenma, during his attack on Tartarus with Azazel's team. Tempesta is one of Tenma's most powerful Demons, possessing unmatched physical might and a body comparable to steel, as well as the deadly ability to spread Magical Barrier Particles from his being if defeated or overwhelmed as a last resort.
As an Etherious, he is a being made out of Eternano, and as a creation of the Black Wizard Zeref, is an extraodinary creature, possessing power greater than the average demon. He is ranked as one of Tenma's most powerful subjugated demons, ranked second overall, the only one surpassing him being Mard Geer Tartaros.
- Calamity Curse: