Abi

is a phoenix demon in the form of a human who makes her debut in the episode titled: The Fiery Bird Master, Princess Abi (episode 146) and is present in most of the episodes up until the episode titled: The Demon Linked with the Netherworld (episode 154) where she and her mother Tekkei are slain by Naraku. As far as it is known, Abi lives on a mountain with her mother, a giant bird demon, who is connected to the other-realm. Abi herself is in control of large flocks of phoenix demon birds, although they resemble pterodactyls more than actual birds, who have the ability to "suck" blood then somehow regurgitate it and withstand being lit on fire as seen when they burn through houses.

During the Story
Princess Abi and her mother become Naraku's pawns for getting the final sacred jewel shard the minute Naraku learns of them. At the time Abi and her mother appear in the anime, Abi's mother is sick from consuming a poisonous demon, which looks like a quad-pedal goblin/spider that has three toes on each foot and an olive/forest green color to its skin (with the exception of the "spider half" which is a seemingly furry yellow). Abi has been using her demon bird flocks to attack and suck the blood from humans in the surrounding villages, using the human blood to dilute the demon poison that harms her mother. Both Inuyasha's group and Naraku hear of the destruction she causes in her search for human blood and while Inuyasha's group goes from village to village finding more victims of Abi's birds, Naraku goes to meet Abi and puts his plan in motion. He offers to help Abi collect more human blood then she could ever manage on her own, as well as a three-point trident made from his bones and an unmentioned as well as unknown reward, in exchange for creating a path to the netherworld for him.

They are then seen discussing the matter back at Abi's nest and Naraku inquires about Abi's mother. He then gives her the trident and they are interrupted by the apparent "sons" of the demon Abi's mother consumed, Naraku takes the liberty of destroying them himself, then returns to talking with Abi. Before Naraku leaves, he gives Abi a Saimyōshō hive, stating that they will help her (meaning against Miroku's Wind Tunnel ) and leaves.

In the other episodes that Abi is involved in, she fights Inuyasha several times, all resulting in her retreat, and continuously collecting more human blood. It is also during this time that she and her mother decide to betray Naraku, and seize their chance when they realize Naraku has ties with a human castle.

During Abi's attack, Inuyasha's group goes to confront her. This ends in her fleeing again and returning to her, now well, mother. Naraku then appears and Abi's mother reveals herself. About the size of the mountain she had been hiding in, Abi's mother is a colossal bird demon, looking vaguely like a giant white chicken with a green beak, yellow legs, red markings around each eye as well as a red tail and claws, and surrounded in blue flames. She, like her daughter, can fly and attacks with fire. After a bit of fighting between Naraku and the pair of bird demons, he is swallowed, barrier and all by Abi's mother. Little do they know that they had fallen into Naraku's trap. Inuyasha's group arrives at the scene and a bit of dialog passes between the two groups, which leads to fighting. Not long after a few blows are exchanged, tentacles appear as they gorge a hole in Tekkei's head. Naraku emerges and more dialog ensues, and when Abi tries to attack him, Naraku withdraws his trident back into his body, taking Abi's right arm with it. In a blind rage Abi continues her attack on Naraku, and Naraku reveals the final reward for helping him.

He then stabs her through the chest with multiple grey tentacles, effectively killing her. Abi disappears, seeming to disintegrate into black dust and then into nothing.

Only after her and her mother's deaths in the next episode, is Naraku's gate revealed. He beheads Tekkei and her blood flows down the remains of their mountain like a river. By merely following this river one can go to the land of the dead, the Netherworld since Tekkei was linked to it. But as soon as the blood stops flowing, the gate will be shut, so Naraku follows it, hovering above it while surrounded by his barrier, with Inuyasha's group following soon after.

Powers and Abilities
Great Demonic Power: As Abi is the princess and second-in-command of the Demon Birds, she is no doubt a powerful demon though given that she's only the princess her mother, Tekkei, is much more powerful than she is. Abi has proved herself to be capable of great threat to many human populace and was able to easily combat against Inuyasha and his group with some of her demon birds (though she had help from Naraku).

Pyrokinesis: Abi was able to shoot streams and balls of fire from her hands and set her demon birds on fire with a wave of her hand. Being an experienced fire user she showed great proficiency.

Flight: Abi is able to fly with flames under her feet similar to Kirara.

Transformation: Abi is able to undergo a transformation where her hands become claws with huge talons and her eyes become blood red; the area around her eyes become darker similar to when Sesshōmaru gets angry. All of her attacks power becoming drastically increased in power. It is also possible that she hadn't fully transformed and her true form is much larger than she appears, similar appearance to her mother.

Enhanced Durability: Abi is somewhat durable as she showed little reaction other than surprise when the trident she was holding on to exploded which destroyed her right arm when Naraku destroyed it by his will.

Weapons
Trident (former): A three-pronged spear lent to her by Naraku after having separated some of his flesh that would serve as an effective tool in combating Inuyasha and his group as Naraku is well aware that Abi would eventually run into them. After Inuyasha and his group arrived at the mountain range, Naraku revealed himself to be alive within Tekkei whom he killed from the inside out which enraged Abi into attacking with the trident but he destroyed it through his will along with her right arm.
 * Barrier: With Naraku's trident she is able to put up the same barrier that Naraku has. Whether her barrier has the same strength as Naraku's is unknown but it is likely as it was able to block both Inuyasha's Wind Scar and Red Tessaiga.
 * Shōki: The trident is also capable of allowing Abi to produce and control miasma like Naraku, though as this is not her specialty and the trident is only a fragment of Naraku's flesh it's unlikely to have as much power as Naraku himself.

Trivia

 * Abi bares a resemblance to Kodachi Kuno from Ranma ½. Both of whom share the same Japanese and English voice actors.

Prinzessin Abi Princesa Abi 阿毘公主 Puteri Abi