Tōga

The was a powerful Inu daiyōkai who was known throughout feudal Japan. He fathered two sons, the second of which was the hanyō Inuyasha from the human woman Izayoi. His first-born son was the daiyōkai Sesshōmaru, mothered by a dog demoness. Two hundred years before the shattering of the Shikon no Tama, he stopped the invasion of a lead by the Lord Hyōga and his son Menōmaru. Long before this, he defeated the Panther King after the tribe attempted to take over the western lands he ruled.

He had many adversaries during his lifetime, and many of them have ended up crossing paths with one or both of his sons many years later.

History
The Inu no Taishō survived long enough to save his wife Izayoi and their newborn child Inuyasha; still weak from his battle with Ryūkotsusei, he dies defending them from a human foe named Takemaru. The gateway to his tomb is hidden in a black pearl (a mystical gem that creates a path between the mortal and spirit worlds) inside Inuyasha's right eye, which was created by Hōsenki, an oyster demon, on the Inu no Taishō's command. Within the pearl, their father's body is shown as an enormous dog skeleton in a suit of armor: his true form, according to Myōga. The sword Tessaiga, forged from the Inu no Taishō's own fang, rests inside this cavernous skeleton, protected by a barrier that repels any non-human with malice toward humans. Because of this, Inuyasha inherits the sword rather than Sesshōmaru. This also suggests Inuyasha's father was never bigoted toward humans nor was he evil. Sesshōmaru even says that he had a "merciful heart for humankind." It seems that he did have a sense of honor and perhaps wanted both his kind and the human race to live in peace.

He acted as the lord of the western provinces of Japan, gaining many other yōkai allies, but also retaining a fondness for humans. This baffles his first wife, Sesshōmaru's mother, who is merely indifferent towards humans and views them mostly as a source of food.

While the Inu no Taishō did not harm humans, he often faced challenges&mdash;or made them&mdash;with other powerful demons; his earliest known adversary was Shishinki, who lost half of his face and had part of his Meidō Zangetsuha absorbed by the Tessaiga. However, since it was an incomplete and unstable technique, the Inu no Taishō sealed it within Tenseiga. The second known challenge came from the Panther demon tribe, when Sesshōmaru was a mature demon; however, the war was settled when the Dog General slew the Panther King.

Although the Inu no Taishō loved his family, his relationship with Sesshōmaru was shown to be distant- if not openly hostile- in the third film. Sesshōmaru's hatred for humans at the start of the series is even greater than his mother's, as we never hear her say a word against Inuyasha or Izayoi. Yet, he clearly admires his father, and wishes to emulate his victory over many powerful demons. Sesshōmaru's mother seems to have been unfazed by the Inu no Taishō's relationship with Izayoi - merely noting his odd fascination with humans, and still speaking affectionately of him when Sesshōmaru came calling.

At some point, the Inu no Taishō fell in love with a human princess named Izayoi; while he continued traveling and challenging great demons (occasionally crossing paths with Sesshōmaru, who would ignore his advice) he would always come back to her, and she eventually became pregnant. However, a samurai named Takemaru who served Izayoi's castle was also in love with her. While the Inu no Taishō was away battling a new demon (the dragon Ryūkotsusei) Takemaru discovered that Izayoi's pregnancy was the result of a tryst with a yōkai, and sought to prevent the hanyō child from being born.

Inu no Taishō had finally met his match. Although he managed to seal Ryūkotsusei into a cliff while in his true form, he was unable to deliver a fatal blow, and he suffered lethal wounds. Myōga then brought him the knowledge that Takemaru was after Izayoi and his unborn son. Sesshōmaru sensed his father's imminent demise and demanded he bequeath him his swords Tessaiga and Sō'unga. The Inu no Taishō refused to give them to him, asking if he was willing to kill him for them. Sesshōmaru stated that he wished to match his father's power by gaining one of the swords, so the Inu no Taishō asked him if he had something to protect. Not realizing that his father had always been trying to teach him compassion, Sesshōmaru scoffed, deriding the need to protect something as weakness. It was this belief that truly cemented his hatred for Inuyasha centuries later, as he blamed the Dog General's death on his compassionate need to protect his wife and son. The Inu no Taishō then took his true form and, despite Myōga's pleas, went for Izayoi one last time.

Arriving at the castle, he easily overpowered Takemaru's troops with Tessaiga, though suffering further injuries from arrows. Takemaru then challenged him, stating that he had killed Izayoi so that she would not be defiled by birthing a demon. Enraged and grief-stricken, the Inu no Taishō sliced off Takemaru's left arm and raced into the castle, while Takemaru ordered his troops to burn it down. Locating Izayoi's body and her newborn son, the Dog General resurrected her with Tenseiga as the castle burned around them. He covered them with the Robe of the Fire Rat to protect them from the flames, but as they prepared to flee, Takemaru returned. Knowing his injuries were fatal anyway, Inu no Taishō  told Izayoi to flee and live a long life- as well as naming his second son Inuyasha. Throwing aside Tessaiga and Tenseiga, he drew Sō'unga and began battling with Takemaru, as the burning castle collapsed around them. Neither Takemaru nor the Inu no Taishō survived.

The Inu no Taisho's remains, along with Tessaiga, were consigned to the gateway region of the Netherworld - the gateway itself sealed within a black pearl that was hidden in Inuyasha's eye. This was the first of many indications that he reserved the mastery of Tessaiga for his younger son. Myōga had been charged with keeping an eye on Inuyasha and helping him access the inheritance when he was old enough. Also in accordance with his will, Tōtōsai 'delivered' Tenseiga to Sesshōmaru (nailing it to Bokusenō's trunk with a sarcastic note, knowing Sesshōmaru would probably try to kill him). No plan was left for Sō'unga as it was too unstable of a weapon, so it was sealed and thrown into the Bone-Eater's Well. After Sō'unga was finally consigned to Hell by the two brothers, Inu no Taishō's soul briefly appeared before them, expressing his pride. By the end of the series his deepest wishes have been granted: Inuyasha has found a secure and happy life with Kagome and his friends, despite his half-demon heritage. Meanwhile Sesshōmaru has been taught the values of compassion, which balance his constant search for power and create a strong bond with his human ward, Rin.

While the various demons in the Inu no Taishō's service scattered after his death, they remained loyal to his memory and showed deep respect to Sesshōmaru and - less frequently- Inuyasha. When the Panther tribe attacked again, all of the Inu no Taishō's former allies joined to form an army under the command of Sesshōmaru, and once more drove them back.

Personality
His personality is more similar to Inuyasha's, tend to make outbursts while having little composure in battle. He also loved Izayoi dearly as well as his two sons. He was also stated to have compassion for humans by Sesshōmaru. Despite his compassion, he was capable of being ruthless when need be to both humans and demons. This was shown when Izayoi begged Takemaru to take his men and leave the palace grounds, not wanting him to be killed by Inū no Taishō.

Outfit
Inu no Taishō dressed similarly to his son Sesshōmaru, in that he wore a white kimono and hakama, armored boots, and a long flowing sash, with the latter two suggestive of Chinese influence.They also share similar breastplates, with a spiked rim, with the addition of Chinese vambraces and armored gauntlets, as well as layered spiked pauldron on each shoulder. He wears a parted pelt that extends from both shoulders and trails behind him as he walks; representing the two streaks of fur running down the back of his yōkai form. His white hair is only seen in a very high ponytail. The Tessaiga and Tenseiga are worn at his waist, while the Sō'unga is worn across his back.

Powers & Abilities
Much of the Inu no Taishō's abilities are unknown, but it is known that he could change his appearance to resemble that of a human's, much like Sesshōmaru. His true form was that of a gigantic dog with a single blue jagged-like stripe on each cheek and twin streaks of fur running down his back. He was much larger than both Sesshōmaru's and Sesshōmaru's mother's yōkai forms. He has been stated to be one of the most powerful yōkai by Myōga and Tōtōsai. Despite his great power, he was unable to kill Ryūkotsusei and was only able to defeat him by sealing his powers away, but suffered fatal wounds in the process. Despite having suffered fatal wounds, his enhanced anatomy enabled him to travel an incredibly long distance and defeat several humans to save Izayoi and his newborn son Inuyasha and fighting off Takemaru before succumbing to his wounds. Eventually, both of his sons, Sesshōmaru and Inuyasha, surpass him in power.

He also commanded the three swords of Supreme conquest: Sō'unga, Tessaiga and the Tenseiga, effectively giving him the ability to manipulate the dead, the ability to resurrect the dead, and the power of destruction. He also is shown wielding the Tessaiga and the Sō'unga quite easily.

Aside from his immense strength, the Inu no Taishō also had incredible foresight, with some of his actions having a hidden message behind them. He entrusted the Tessaiga to his son Inuyasha, accurately predicting that he needed the sword to protect himself, as well as another, namely Kagome. He bequeathed the healing sword Tenseiga to his eldest son, Sesshōmaru, in order to teach him compassion. Tōtōsai eventually reforged the Tenseiga into a weapon, giving it the ability to perform the Meidō Zangetsuha, presumably on the Inu no Taishō's orders.

It can be assumed that the Inu no Taishō was capable of creating barriers as he was able to put a barrier on Tessaiga.

Weapons

 * Tessaiga: Also known as the Sword of Earth, the Tessaiga was created from the fang of the Inu no Taishō. He created it to protect Izayoi, Inuyasha's human mother. It is capable of destroying one hundred demons with a single stroke, using the Kaze no Kizu and the Bakuryūha. In his will, the Inu no Taishō left the Tessaiga to his youngest son, Inuyasha.
 * Tenseiga: Also called the Sword of Heaven, the Tenseiga was created from the fang of the Inu no Taishō. It is capable of reviving the dead of one hundred beings, whether demon or human, with one stroke. Tenseiga cannot cut the living but can cut spirits and the living dead. In his will, the Inu no Taishō left the Tenseiga to his eldest son, Sesshōmaru.
 * Sō'unga: Also called the Sword of Hell, the Sō'unga is a demon sword that the Inu no Taishō possessed and contained. It has the ability to control the dead and open a gate to hell. Inu no Taishō's hope was that one day his sons would be able to find the answer to sealing Sō'unga for good. It was never mentioned in the Anime or the Manga, but it appeared in the 3rd movie.

Family
The Inu no Taishō's mate and mother of his first and full-yōkai son, Sesshōmaru. He left her the Meidō Stone as well as information regarding Tenseiga. Given that Tenseiga was broken from Tessaiga, and that Tessaiga was forged to protect Izayoi (thus Tenseiga did not exist until after he had feelings for Izayoi), then it can be assumed that the Inu no Taishō and Sesshōmaru's mother remained on good terms even though he left her for Izayoi up until his death.
 * Sesshōmaru's mother

It is unknown when they first met, but they ended up falling in love and married which resulted in having a half-demon child, Inuyasha. After his last battle with Ryūkotsusei, he rushed to save her without first tending to his wounds. He fought through the soldiers only to find her already dead. Using the Tenseiga, he brought her back to life, giving her the Robe of the Fire-Rat, and telling her to escape with their newborn son whom he names Inuyasha. His last words were: "Izayoi...You must live. Live a long life. Live long and well with Inuyasha." This showed that the Great Dog Demon did deeply care about his sons, not seeing them as tools of heritage.
 * Izayoi

Being born only moments before the Inu no Taishō's death, Inuyasha never met his father. After saving Izayoi from Takemaru with Tenseiga, he named his son Inuyasha. According to Myōga, Inuyasha is able to use his sword Tessaiga because he protects Kagome, who is human, mirroring the Inu no Taishō's relationship with Izayoi.
 * Inuyasha

The Inu no Taishō's relationship with his first son was somewhat strained because of the former's relationship with the human Izayoi. Sesshōmaru was greatly annoyed with the fact that his father left Inuyasha, his hanyō brother, the Tessaiga and not him. In Swords of an Honorable Ruler, one moonlit night, his gravely injured father asked him if he had "someone to protect". Sesshōmaru knew that it was his father's final test for him, and Sesshōmaru stated that his answer was "No". So, the Tenseiga was passed to him after his father died saving Inuyasha and Izayoi. At first Sesshōmaru felt nothing for the Tenseiga as it had no destructive power whatsoever, but as time passed, he started to understand and respect its power. He also came to understand his father's cryptic words. Upon meeting the human child Rin, his attitude toward humans changed. Sesshōmaru felt he should protect the young girl. With something to protect (Rin, Jaken, and sometimes Inuyasha), Sesshōmaru became a very powerful daiyōkai, just as his father intended for him. While Sesshōmaru never expresses any sort of emotional attachment to either of his parents, he still has great respect for his father's power and wishes to emulate and surpass it. The Inu no Taishō cares for his elder son, but is often frustrated with his callous attitude towards humans and his focus on power above anything else. Ironically, Sesshōmaru ends up protecting a human just as his father did.
 * Sesshōmaru

Allies
Myōga was the Inu no Taishō's closest vassal and adviser, serving under him for many years. Throughout the series, Sesshōmaru and Inuyasha encounter their father's numerous enemies, and Myōga is usually the only person who is able to shed light on them and what they're after, a few prime examples being Ryukotsusei, Hyōga, and Shishinki. Myōga ends up being Inuyasha's vassal throughout the series, giving advice and sharing wisdom just as he did for his father. He's fiercely loyal to his first lord as well, becoming upset when Inuyasha says he doesn't care about avenging his father.
 * Myōga

Tōtōsai was the demon blacksmith who crafted both the Tessaiga and Tenseiga from Inu no Taishō's fangs. He was also entrusted with bequeathing the two swords to the his sons after Inu no Taishō's death, giving Sesshōmaru the Tenseiga, and Inuyasha the Tessaiga. In the anime, Tōtōsai says that giving the elder brother Tenseiga and the younger brother Tessaiga was Inu no Taishō's dying wish. Tōtōsai was also given instructions by Inu no Taishō about Meidō Zangetsuha, and how to show Sesshōmaru the path to true power.
 * Tōtōsai

A wise tree yōkai and old friend, Bokusenō donated boughs of his own wood from which to carve the scabbards of Tessaiga and Tenseiga.
 * Bokusenō

Enemies
A dragon demon with powers that resemble lightning. Inu no Taishō only managed to seal him to a cliff with his claw. According to Myōga, Ryūkotsusei was much too powerful to kill. It is implied that the wounds Inu no Taishō received in that battle led to his demise during his battle with Takemaru of Setsuna in the third movie. Many years later, Naraku releases Ryūkotsusei's seal hoping the dragon would kill Inuyasha, who was there to defeat Ryūkotsusei.
 * Ryūkotsusei

A moth demon from "the Continent", or as some have inferred, China. This is yet another demon that Inu no Taishō managed to seal but not defeat. Sealed within the Tree of Ages, Hyōga is absorbed by his son and successor Menōmaru, who in turn tries to kill Inuyasha and absorb all living souls on earth.
 * Hyōga

The original wielder of the Meidō Zangetsuha. The battle between him and Inu no Taishō is implied to be inconclusive though it is revealed Shishinki was terribly injured. He seeks to kill Inuyasha and Sesshōmaru as revenge for stealing his technique.
 * Shishinki

A demon that Inu no Taishō managed to defeat long ago. He was revived by his tribe using sacred jewel shards. The Panther King was destroyed by Inuyasha and Sesshōmaru.
 * Panther King

A human who was in love with Izayoi. Takemaru loved Izayoi and believed that her heart had been captured by Inu no Taishō. Takemaru then fought with Inu no Taishō and lost his left arm. Takemaru then ordered his men to set the mansion on fire, with Izayoi, Inuyasha, and Inu no Taishō still inside. He then followed Inu no Taishō into the mansion and fought him to the death inside the burning mansion while Izayoi escaped with Inuyasha.
 * Takemaru

Trivia

 * Many fans have referred to him by name as Tōga. "Tōga-ō" (闘牙王, Fighting Fang King) was his name in the third movie script and appeared in one trailer and the original draft of the soundtrack, but the name was scrapped for unknown reasons.
 * It's interesting to note that while the Inu no Taishō is Inuyasha's only demonic parent, they do share markings when Inuyasha is in his full demon form. However, while the Inu no Taishō has a single blue stripe on either cheek, Sesshōmaru has two magenta stripes on either of his cheeks, as well as his mother does, it is not known from which parent he obtained the double magenta stripes.
 * In the manga, the Inu no Taishō's humanoid form never appeared, only his true form, however, author Rumiko Takahashi personally designed his human form for the third movie. These designs appeared in an issue of Shōnen Sunday.
 * Many fans refer to him as Lord of the Western Lands, however such a designation appears nowhere in any incarnation of the series. He was never stated to have any land holdings or official political power other than holding the title of "General" and being "based in the western provinces". After Sesshōmaru discovered that his father had intended for Tenseiga to be re-absorbed by Tessaiga, he lamented that this meant that his father intended to "leave him with nothing", indicating that Tenseiga was his sole inheritance from his father, and he did not inherit any land, title, or followers.
 * Inu no Taishō, Sesshomaru, Sesshomaru's mother and Inuyasha are mostly or at least partly based off of the Inugami, a Japanese dog-like demon. Japanese folklore describes Inugami as zoomorphic, or anthropomorphic, dog-like beings, often similar to werewolves.
 * The Inu no Taishō 's age is never revealed in the movie but given that in his original design he has the mature appearance of a man in his late 30s to early 40s he is a lot older than he looks many have believed him to have been close or over 3000+ years old when he died.