Sesshoumaru
The elder half-brother to Inu-Yasha and the Lord of the Western Lands in Feudal Japan. Sesshoumaru was a full-blooded Dog Demon, and a ruthless and powerful one at that.
After the death of their father, they two half-brothers were bestowed upon them two swords made from their father's fangs by the smith Totosai. Sesshoumaru was given the Tenseiga, which gave him the power to heal and save lives of human beings. Sesshoumaru despised this gift, as he held nothing but contempt for human beings, and even more contempt for his younger half-brother Inu Yasha.
Sesshoumaru spent the next fifty years searching for his father's tomb (with his retainor Jakken) in order to possess the other sword, the Tetsuaiga, and eventually found it within Inu Yasha himself. He made a failed attempt to take the sword, but it was soon claimed by Inu Yasha as his birthright, and in the ensuing battle, Sesshoumaru's left arm was severed.
For the next few weeks, Sesshoumaru was taking the arms of other demons for his own use, but none would last too long. It was at this time that he was offered a human arm with a shard of Jewel of Four Souls by the mysterious demon Naraku in order for him to hold the Tetsuaiga. While Sesshoumaru briefly held the sword, it was reclaimed by Inu Yasha, and the new arm almost destroyed Sesshoumaru. Sesshoumaru promised to one day take revenge on Naraku.
Sesshoumaru next tracked down Totosai and ordered him to forge him a new sword to rival Tetsuaiga, but the smith refused, and in the next battle Sesshoumaru was nearly destroyed by the sword when Inu-Yasha discovered the Wind Scar, but the Tenseiga saved it's master's life.
While recovering, a young human girl named Rin came upon Sesshoumaru and showed him kindness. In spite of himself, when Rin was later killed by wolves, Sesshoumaru used the Tenseiga to restore her to life. Rin then began tagging along with Sesshoumaru much to the chagrin of Jakken.
Sesshoumaru later used the fang of Goshinki to commision a former apprentice of Totosai, Kaijimbo, to forge him a new sword the Toukijin, and upon claiming it, grew much more powerful. The Wind Demon Kagura even became a little infatuated with him, as she felt he was now powerful enough to destroy Naraku.
Sesshoumaru recently appeared to stop Inu Yasha after his younger brother went full demon and went on a rampage. While he spared Inu Yasha's life, Sesshoumaru still one day intends to kill him, and take the Tetsuaiga.
But most recently, Kagura tried to bribe Sesshoumaru to kill Naraku for her and offered him shards of the Jewel of Four Souls as payment. Sesshoumaru declined, saying that he had no interest in the sacred jewel, and that Kagura should be willing to fight Naraku by herself before asking any one for help. Kagura viciously insulted Sesshoumaru before flying off.
(Sesshoumaru has two forms, his regular "humanoid" form which we normally see him in, and his gigantic Dog Demon form.)
