Yuji Sakai : : is a high school student who, as Kentaro reveals following Chigusa's pregnancy, had an older twin brother who died at birth; in honor of him, his parents named him Yuji, which means "second (child) who shall live long". One day, he discovers that he is a Torch who has already died and has little time left before he disappears. However, he is a Mystes who contains the , a Treasure Tool which restores his Power of Existence each midnight. Because of this, he can live a regular lifespan as long as his Power of Existence does not run out before midnight, but it is unknown whether he will age normally or be immortal. Yuji is training to use his Power of Existence in hopes of fighting alongside Shana, which is later revealed to be equal to that of a Crimson Lord because Hecate altered his Power. After learning of his status as a Torch, Yuji develops a somewhat optimistic, yet fatalistic outlook on life. He puts others' needs before himself and justifies his acts of heroism with the belief that even if his existence is eventually extinguished, his sacrifices will be proof that he once lived. Although Yuji initially lacks the training and discipline of a Flame Haze, he makes up for this through his intellect, as he thinks outside the box and solves issues in ways that others would not. Over time, Yuji's training enables him to avoid most attacks even from Flame Hazes as skilled as Shana and Wilhelmina, and he gains the ability to cast Power of Unrestraint. He also wields Blutsauger and can infuse it with some of his power, as well as attack with silver fire. :When Yuji first activates the Seal on his own, the silver flames are an omen of the Snake of the Festival's return, as the God of Creation, which is revealed to be the Snake himself, created the flames to collect the elements needed for his resurrection. It is revealed that there are two entities inside the Midnight Lost Child: Johan, Pheles' lover and its creator, and the Snake of the Festival, a Crimson Lord who is one of the Crimson Realm's true gods and Bal Masqué's founder/true leader. Later, Pheles' second attempt to free Johan causes the Snake to awaken and he merges with Yuji, demanding that his subordinates refer to him as their new leader. As a result, others are confused as to his true intentions, as it is difficult to distinguish which actions are Yuji's will of Yuji and which are the Snake's. As the Snake plans to create Xanadu, a new world between the two realms which would allow the Denizens and Crimson Lords to live peacefully and end the conflict between the Flame Hazes and Bal Masqué, Shana and her allies oppose his plan, fearing that Xanadu's eventual collapse would further degrade the balance between the worlds. In the final battle, Yuji uses his own Unrestricted Spell, which he primarily uses as a shield, but its versatility is bound only by his will. When Lamia enters Xanadu after fulfilling his wish, she grants Yuji a new Unrestricted Spell, Grammatica, which restores his existence after he accepts Shana's feelings and they kiss, making him human again. With the help of another spell from Lamia, Yuji restores the humans in Misaki City whose existence the Denizens absorbed before departing for Xanadu with Shana.
Shana : : is a Flame Haze known as the , who hunts the Denizens and contracted with Alastor, who calls her "The Great One". Her mentor and guardian is Wilhelmina Carmel. She generally treats most people with ignorance and indifference, with the exception of Chigusa Sakai, to whom she looks as a source of answers when Alastor or Wilhelmina cannot. At first, she focuses solely on her duty as a Flame Haze and is indifferent towards humans, choosing not to have a name until Yuji names her Shana after her weapon, a
nodachi called the , and seeing him only as a Torch notable for his status as a Mystes. Despite her harsh attitude towards Yuji, she genuinely cares for him as she slowly opens up to him and comes to see him as a person, eventually falling in love with him while competing with Kazumi Yoshida for his love. Shana is said to be the most powerful Flame Haze, who most Denizens known and fear. She has various abilities, including proficiency with the Nietono no Shana, psychic abilities, wielding flames and the Power of Existence, and flying with wings of flame. After the final battle, Yuji accepts Shana's feelings and asks her to be with him in Xanadu, which she accepts.
Alastor : : is the Crimson Realm's Lord and one of its true gods, who Shana contracted with, and is known as the . He expresses his will through a divine vessel called the Cocytus, which, in Shana's case, takes the form of a pendant. Alastor is considered to be among the strongest of the Crimson Lords and Denizens, but despite his power, he tries to keep the Denizens from consuming the Power of Existence. Unlike other Crimson Lords who have a Flame Haze, his contractor can perform Divine Summoning (神威召喚 Shin'i Shoukan, God's Power Summoning), a method called , which requires a lot of Power of Existence and will manifest his being as the in the form of a giant minotaur to consume Denizens around him. This method is his Flame Haze's last resort, as prior to Shana, no Flame Haze had survived after using it. Alastor and Shana seem to have a parent-child dynamic at first, but he is aware that Shana must grow up and adapt to the world.
Snake of the Festival : :The is a Crimson Lord and one of the Crimson Realm's true gods, who is known as the , and Bal Masqué's leader, who was contracted to Yuji after merging with him. Although he has a kind and noble side that he shows to his comrades and subjects, he is cruel and willing to do whatever it takes to ensure that his plans come to fruition. Long ago, he received many prayers from Denizens to create a world for themselves, which he answered by initiating the ritual to build a world called the , which was to be a paradise for Denizens. However, the process required many human lives to complete using their Power of Existence, and the ancient Flame Hazes, including Tis and Khamsin, intercepted and disrupted the ritual. causing a distortion that sealed the Snake in the rift between the worlds. The Snake's Divine Summoning, , unleashes his power as the God of Creation and summons his power over Creation and Settlement to create anything. However, it requires a large amount of Power of Existence, which is why Bal Masqué seeks the Midnight Lost Child. Like other summonings, it requires a sacrifice; when it is used to create Xanadu, Hecate is used as the sacrifice. ==Humans==