Omachi

About
Omachi is the Northern Guardian of the One Eyed House. Originally, she was the previous Youkai King, known as Her Knowledgeable Highness the Nine-tails Fox of Insane Star (狂星九尾・未知女殿, Kyouseikyuubi Matsuchi-joten), and led the Great Youkai War against the humans. Her violent war against the humans led JAPANese to be truly scared of youkais, since the battle took many lives and she went to extremes in attempt to secure her victory. Probably her most famous, ruthless and insane move was the release of the Forbidden Youkai, the Soul Binder, which brought a terrific curse that spreads like an epidemic, which took the lives of countless people. She was eventually defeated by an alliance of One Eyed Masamune with the Oda House.

After she was defeated by Masamune, she fell in love with him, stepped down as the Youkai King, and faithfully followed Masamune from then on. She's arguably the wife of Masamune that loves him the most at present. With time, she became aware of the suffering she caused in the Great Youkai War and doesn't like being in  Owari  because she was responsible for the death of the father of  Kouhime  and  Nobunaga.

In battle, Omachi's powers are absolutely terrific, being an extremely proficient and talented user of the Yin Yang arts. She relies mostly in using thunders to crush her opponents, and all her attacks cover a huge range while being pretty devastating as well. Her biggest weakness is that she's pretty fragile and  immobile, but when given a proper back-up and cover, she can easily destroy armies by herself.

During the events of Sengoku Rance, when the Oda House led by Rance declares war to the Youkai country to the northeast, she eventually leaves Masamune's side for a while to take part in the battefield as a commander. Despite possessing incredible power, she was defeated by the opposing army and turned into a stone. After the war was over, Masamune turned her back to normal and joined the Rance's Army, seeing that Masamune joined him as well after the war was over.