Tsubaki

was the only seen dark priestess. She was the arch rival of Kikyo.

History
In her youth, Tsubaki was a gifted priestess, her talents were magnificent and she progressed really quickly in her training. Tsubaki was seen as a high class priestess who was shown to have garnered respect from other priestesses, even Kikyo; however, she saw Kikyo as a rival as Kikyo's spiritual powers rivaled hers. Not knowing Kikyo's powers had far surpassed her's.

When Kikyo was given the Sacred Jewel to guard, Tsubaki was jealous of Kikyo having been given such an important job. Tsubaki confronted her master to inquire as to why Kikyo was given the Sacred Jewel to protect and not her, but Tsubaki's master didn't say anything. Tsubaki stormed off, leaving her master behind feeling sad for his disciple. It can be assumed that the reason why Tsubaki's master didn't tell her why she was given the jewel is because he didn't want to upset her, due to her heart not being pure.

Tsubaki later confronted Kikyo in a forest and attempted to cast a curse on her using her Shikikami. However, Kikyo used her bow to block the curse and sent it flying back at Tsubaki, which gave her a scar on her right eye. This caused Tsubaki to hunger for revenge on Kikyo seeing her as a mortal enemy ever since. Somewhere between the past events and current events, Tsubaki made a deal with a demon and sold her soul to retain her youth and beauty.

In the Story
When Tsubaki encountered Kagome Higurashi (Kikyo's reincarnation), she took every opportunity she could to get her revenge, thus, making her a victim to Naraku's manipulation. She is given an almost complete Shikon no Tama.

Tsubaki places a curse on Kagome and during her battle with Inuyasha, she threatens Inuyasha with Kagome's life, until Kagome attacks her with her sacred arrow, because of this Tsubaki begins to focus her attack on Kagome.

During battle, Tsubaki underestimated Kagome's skill and taunted her with the fact that her skills did not compare to those of Kikyo. In the end, Tsubaki was defeated by Kagome's spiritual power. Because she underestimated her abilities, her curse was thrown back at her just like it was 50 years ago. In the manga, she isn't seen again.

In the anime, however, she appears and was able to escape to the shrine where she used to train. Tsubaki tricked the two priestess trainees into helping her fight Inuyasha, while she plans to awaken the sealed demon. Kagura then appears to take back the Sacred Jewel, but Tsubaki refused to part with it.

Tsubaki unlocked the seal that trapped the ogre demon in the Forbidden Tower, and to increase her power, absorbs the ogre. When InuYasha and his group arrived, she transforms into a half-ogre form and attacks InuYasha and the rest, however, in the end she was defeated by Inuyasha's Backlash Wave. During her attempt to use the Sacred Jewel, a Demon Wasp emerges out her eye and takes the Sacred Jewel, thus taking her spiritual powers along with the Shikon no Tama. Tsubaki's appearance begins to turn into her actual age. With her last breath, she regrets trusting Naraku, underestimating and losing to Inuyasha, and she turns into dust as she shouts that she was the most powerful priestess.

Relationships

 * Kikyo- Tsubaki hated Kikyo and saw her as a rival. Tsubaki hated her to the point of wanting her to die and and this continued even after she (Kikyo) was reborn. This conflict can be seen as one-sided, as Kikyo didn't express any anger toward her and was seen feeling sympathy for her when she died.


 * Kagome- Due to Kagome being the reincarnation of Kikyo, Tsubaki despises Kagome and attempts to kill her just like she did Kikyo, however, despite the hatred she seemed to respect her power as with her dying breath, she said she regretted underestimating Kagome's ability.


 * Naraku- Tsubaki, despite being given the almost complete sacred jewel by Naraku, does not trust him that much. At first, she is impressed with his cruelty towards Inuyasha and Kagome, due to his plot forcing Kagome to try and kill Inuyasha like Kikyo did 50 years ago. But after her failure, she begins to realize she is just another pawn to him.

Powers and Abilities
As a Priestess, Tsubaki had a range of Spiritual powers and she was shown to be quite a powerful priestess in her youth. She was shown to have a high level of spiritual power when she easily broke the numbers of seals that was placed to trap the Ogre Demon created by Sages before her.
 * Shikigami - Tsubaki's proficiency in black magic comes in the form of summoning a demon puppet which comes in the form of a serpent-like creature capable of cursing even the most pure of essences, such as tainting the Shikon Jewel and Kagome.
 * Sutra Magic - Tsubaki was seen to be able to use sutra.
 * Spiritual Power - Tsubaki's spiritual powers had once made her on par with her rival, Kikyo. However it had been diminished significantly when her Shikigami was reflected back at her.
 * Demon summoning - At the height of her black priestess power, Tsubaki had the ability to harbor a slew of demons in her cursed eye, all bound by her whims.

Manga vs. Anime

 * In the anime, it was said that the reason why Kikyo lost her powers when she fell in love with Inuyasha (which wasn't mentioned in the manga) is because she placed a curse on Kikyo.

Trivia

 * Tsubaki is the first and only dark priestess shown in InuYasha
 * Sharon Alexander, who plays Tsubaki in the English Dubbed version of Inuyasha, also plays Kanta