Tatsuki

Tatsuki (竜姫) was the 3rd seat on the Council of Twelve. Shortly after Masamori Sumimura joins the group, she attempts to seduce him and steal his membership badge. She later resigned from her post, apparently frustrated with the way the Shadow Organization was rapidly falling apart. However, she secretly began to organize a resistance movement with the other resigned leaders.

Appearance
While Tatsuki looks young, Shichirou Ougi estimates her age to be around 300 when Masamori Sumimura asks, though neither are foolish enough to ask her. Her hair is pale and usually held in place by two pins. She also has two elongated fangs that protrude from her top teeth, though they're usually only visible when she smiles. She sometimes wears pants that have tiger stripes similar to her dragon form.

Personality
Tatsuki is generally friendly (sometimes too much so) with her comrades. She has a playful nature, and especially enjoys teasing Masamori Sumimura and Nura Kidoin. She can be easily bored or frustrated, but her natural charisma and enormous power ensures that she always has allies, so that even those who disagree with her never oppose her directly.

History
Tatsuki was born in Ryusenkyo, a land known for often producing people with Ayakashi blood. She commands a great deal of influence, both because of her great power and her outgoing attitude: she used to associate with Nizou Ougi in their younger days, and the two were fond of causing destruction, calling themselves Fujin (風神, God of Wind) and Raijin (雷神, God of Thunder and Lightning). Tatsuki maintains an occasional partnership with the Ougi Clan, and also has a close friendship with both Nura Kidoin and Kagen Shiromi's wife.

Introduction
Tatsuki is the only obviously female member of the Council of Twelve from their introduction, though her name isn't revealed until much later. After Masamori's first meeting with the group ends, Ichirou Ougi gives him some advice in the form of a threat. Tatsuki pretends to defend and comfort Masamori, then tries to steal his membership badge (which would have resulted in his being demoted), but Masamori stops her. Both Yumeji Hisaomi and presumably Meian also give Masamori some parting advice, but Tatsuki tells him not to trust "the oldest member here," though it is unclear if she meant Yumeji (who is over 400 years old but able to change bodies) or Meian (the oldest member based on appearance).

Resignation
After the death of Yumeji, Masamori reports to the rest of the council that one of the Sousui's men (and therefore the Sousui himself) was responsible. Several members react with disbelief or outrage, but Meian calms them and suggests that Nura assume leadership of the council. Nura declines, and Tatsuki abruptly resigns out of annoyance, slicing her badge in half. Before leaving, she suggests that Meian take over, which he does after receiving no opposition.

Tatsuki's Resistance
After failing to recruit Nura Kidoin as an ally against the Sousui, Masamori calls in a favor with Shichirou Ougi (earned for choosing to save Rokurou ) to arrange a meeting with "Raijin". At the meeting place in Ryusenkyo, Masamori is continually assaulted by powerful lightning strikes, and eventually collapses even with his Zekkai's protection. The dragon responsible for the attack then transforms into the nude form of Tatsuki, who is then clothed and attended to by two servant girls. Masamori begs her to help him save the Shadow Organization, but Tatsuki reveals that she has already gathered people for that very purpose. She mentions that she is sheltering a miko that has labeled Masamori an important person, and invites him to join them. The meeting takes place at Tatsuki's home, and her comrades are revealed to be Nura Kidoin, Kagen Shiromi, and Shichirou himself. They all agree on a plan to stop the Commander.

Tatsuki meets with an unnamed god to ask him to allow her to handle the current chaos. He allows this only because Tatsuki is extremely powerful, and she promises to show that humans can clean up after themselves. He warns her not to disgrace Hakuma.

Tokimori Hazama meets with Tatsuki. She has spoken with the gods of the surrounding sacred lands, and says they will look the other way so long as Hakuma's power is maintained. Her group will attack the Shadow Organiation Headquarters on the following day's night. Tatsuki believes their odds of victory are very high, and Hazama feels the same about his team. Tatsuki is concerned that disturbing Hakuma's god could be extremely dangerous. Hazama says that she will deal with the outside, and he will deal with the inside, as they agreed. Tatsuki has learned that the god of Hakuma is named Mahora.

Tatsuki discusses her plan for the war with her group. She and Shichirou will create a storm to distance the civilians from the war. Kidoin's ogre army will head directly into the Headquarters. Because of the risk of the Commander's brainwashing, no humans will enter. Shiromi will be Kidoin's advisor, and Masamori will handle the Commander. Tatsuki and Shichirou will have control of the Night Troop and Shiromi's subordinates. As a last resort, if the plan fails, Tatsuki and Shichirou will use all their power to destroy Hakuma, which would mean all of their deaths. Tatsuki asks Shiromi and Masamori to stay behind after the meeting, and explains that Kidoin cannot kill, nor will she order her demons to. Tatsuki provides Masamori with a recent photo of the Commander from the attack on Arashizaki Shrine. Tatsuki stresses that Masamori's role is the most important, because killing the Commander should also end the mental control he has over others.

The War
Tatsuki and Shichirou combine their powers to generate a powerful storm, in order to keep civilians away from the mountain location of the Headquarters. Kidoin's ogres serve as the front line, and because their devotion to Kidoin is so strong, they are immune to the mental control of the Commander's serpents.

The brainwashed executives Juho, Kusaribe Gaiji, Tsumugi Kazuchika, and Meian (with his two Kurokabuto) enter the battle. Tatsuki instructs Shichirou to target the executives, but to be absolutely sure to kill Meian, who can control others. She warns him not to be seen, however, as many are watching, and she wants to use the war as a basis for Kidoin taking over the Shadow Organization.

Haku falls during the battle, and Kidoin is knocked out. Tatsuki is especially concerned, because she sees the Commander's snakes approaching Kidoin, which would instantly end the battle. However, just as Kidoin is possessed, she collapses. Shichirou defeats Juho, and notices serpents fleeing from his body. The serpents all leave the battlefield in one great flood. The formerly brainwashed combatants all wake up. Tatsuki tells Shichirou that they are waiting for medical units, but so far there has been no word on whether or not Masamori has taken out the Commander.

Shichirou asks Tatsuki if the truth behind the Shadow Organization will vanish with the Commander's death. Tatsuki assures him that the Commander has a female log-Keeper at his side that has recorded information since the organization's founding. Tatsuki suspects that the woman is also from her homeland of Ryusenkyo, because people with ayakashi blood are often born there. If so, the woman is over 800 years old.

After the War
The Shadow Organization rebuilds following the war. Kidoin is the new leader, forced into the role by Tatsuki, who is actually running things. According to Masamori, because they are women, they don't desire more power and easily delegate control, resulting in speedy progress. Masaori also reveals that he has been placed in the bottom ranks, as Hazama suggested to Tatsuki that Masamori would grow if he was made to advance slowly.

Powers & Abilities
Master Lightning Manipulator: She can produce massive amounts of lightning at her whim. Even standing near her can kill a normal human being. When using her powers alongside an Ougi Clan member, they are able to generate heavy rains and wind storms with ease.

Flight: Tatsuki is capable of flight without any visible means of support, likely a side effect of her transformation.

Ayakashi Transformation: Dragon: Tatsuki is able to transform into an enormous dragon with tiger-like stripes and wields extremely powerful lightning in this form. She is easily able to overwhelm Masamori Sumimura's Zekkai without using her full strength, leaving him completely exhausted and temporarily paralyzed. When Tatsuki transforms into a human from her dragon form, she's nude and her hair is loose, most likely because the clothes and hair pins are destroyed in the transformation.

Nura Kidoin
Tatsuki is very fond of Nura and the two seem very close. She tends to treat Nura like a child, however, and as with most people, Nura seems unable to refuse Tatsuki.

Masamori Sumimura
Tatsuki enjoys teasing Masamori and testing the limits of his abilities. Masamori has a wary respect of her and Tatsuki has no issues with reminding him how much more powerful she is than him.

Etymology

 * The name Tatsuki means "dragon" (竜) (tatsu) and "princess" (姫) (ki).