Sesshomaru is InuYasha's older half-brother. Like their father, he is the Lord of the Western Lands, although Sesshomaru maintains no permanent home. As a full-blooded Inu-yokai, he is a very powerful demon and nearly unequalled in raw power, but is unable to defeat Naraku in volume twenty-three of the manga. Unlike almost every other sentient demon, aside from those affiliated with his and InuYasha's father in some way, he has no interest in possessing even one shard of the Shikon Jewel to enhance his powers, since he is already supremely confident of his own strength.
Initially, he is ruthless and cruel in his pursuit of Tetsusaiga and his dealings with InuYasha, whom he despises for being a half-demon and consorting with humans. However, Sesshomaru's behavior and attitudes gradually change from the influence of his sword Tenseiga and the human child Rin. His growing compassion finally prompts Tōtōsai to reforge Tenseiga, enabling the Meidou Zangetsuha ("dark path of the dawn's moon blast") attack. After Naraku attempts to manipulate him by using Rin as a hostage, Sesshomaru becomes determined to destroy Naraku. He stops trying to claim or destroy Tetsusaiga, and, while still sometimes hostile in his attitude toward InuYasha, he is sometimes "helpful" in his encounters with InuYasha's group.