Age: Don't know but he's older then Iuyasha, that's for sure
Race: Dog Demon
Weapons: Tessaiga (or known as Tenseiga), Dokkasou (poison flower claw), and Toukijin, his new sword made from Goshinki's fangs (which were able to break apart Tetsusaiga).
Love: Rin *he seems to always protect her, maybe that showes that he cares for her^^;*
Hates: Inuyasha and Naraku
Extra info: Sesshomaru is also known by fans as "Fluffy" ^_^. He is Inuyasha's older half brother, and a full dog demon (youkai). He enjoys fluffy boas, being evil, and bossing around his servant Jaken. By the way, Jaken is the little green demon that follows Sesshomaru around. He feels like he owes Sesshomaru since his people were saved, so he follows Sesshomaru looking for an opportunity to repay him.
Sesshou: Killing, Destruction of life
Maru: Perfection, Purity, Man
Sesshomaru is the aristocratic half-brother of Inuyasha. He is often silent, and allows his actions to speak for him. Unlike his half-brother, Sesshomaru is a full-blooded demon, and his powers are much more developed than those of his young sibling. The white-haired demon is projects a cold exterior to all those around him, as he rarely does anything unless his actions will benefit himself.
Initially Sesshomaru is obsessed with retrieving Tetsusaiga, the sword made from his father's fang that was bequeathed to Inuyasha. Sesshomaru looks down upon his half-brother because of his impure lineage, and believes the Tetsusaiga is too fine a blade for his unworthy sibling. Sesshomaru discovers that regardless of his greater skill with the sword, his father has ensured that he will never be able to use it. In fact, no full-blooded demon would ever be able to touch the blade- therefore only Inuyasha can wield the powerful Tetsusaiga. Sesshomaru and Inuyasha's battle over the Tetsusaiga lead to the loss of Sesshomaru's left arm.
Sesshomaru was instead given the Tenseiga, a sword incapable of harming anyone. Instead the sword is able to revive the recently deceased. Though Sesshomaru rarely makes use of it, Tenseiga has forced him to show a slightly more compassionate side, a side which began to grow after he took in the human orphan girl Rin. Although Sesshomaru remains a cold, self-absorbed individual, he slowly develops a sense of compassion for his human charge. Instead of developing his skill with Tenseiga, Sesshomaru instead makes use of Tokijin, an evil sword made from the teeth of the demon Goshinki. While the blade serves him well it is eventually shattered during a battle with Moryomaru. As Sesshomaru begins to show more compassion and drifts away from acting only in his own interests and using his tainted Tokijin. After seeing that Sesshomaru has learned about compassion Totosai the swordsmith agress to reforge Tenseiga. Tenseiga is transformed into a killing blade capable of opening powerful vortexes into a dark void, as Totosai now has faith that Sesshomaru will wield the sword responsibly.
Prior to meeting Rin, Sesshomaru's only companion was Jaken, the small demon who worked as his underling. Although Sesshomaru seems indifferent and abusive towards the imp, he has shown that he does care about the creature when he revived him from the dead using his Tenseiga.
Sesshomaru is eventually drawn into Inuyasha's battle with Naraku when Rin is kidnapped and used as leverage to make Sesshomaru kill his half-brother. Sesshomaru instead decides to slaughter Naraku. He nearly does, but the demon escapes. In all his battles against Naraku, Sesshomaru is the essence of grace under pressure and makes every battle look easy. He rarely looses his cool, but when he does he becomes unstoppable. Only once has he revealed his true form, a huge white dog, and that was during his battle with Inuyasha over the Tetsusaiga.
The Meaning Behind the Name
"Sessho" means "cruel". "Maru" is a suffix for masculine names. Sesshomaru could be also translated as "killing blade".