Rin Okumura ( Blue Exorcist )

Plot:

Rin Okumura is the fifteen-year-old protagonist of the story and the son of Satan, born from a human woman and an inheritor of Satan's powers.

His powers were sealed at birth into a demon-slaying blade, Kurikara (倶利伽羅), by Mephisto Pheles, the True Cross Academy principal, allowing him to live a normal human life for nearly 15 years with his twin brother Yukio and his foster father Shiro Fujimoto.

Rin becomes aware of his true identity after Kurikara can no longer seal his powers, setting off a chain of events that lead to the death of Shiro at the hands of Satan, who attempts to drag Rin back to the demon realm, Gehenna.

Mephisto Pheles later confronts Rin, who demands Mephisto to let him join the exorcists against the demons. Mephisto personally enrolls Rin into the True Cross Academy so that Rin can pursue his goal to become a Paladin and to defeat Satan.

While currently an Exwire, Rin wishes to obtain the biggest rank of an Exorcist, Paladin, to prove that Fujimoto did not want to use him as a weapon.

Abilities:
Rin can access the power he has inherited from Satan through drawing Kurikara. The sheath acts as a portal to Gehenna, which, when the blade is drawn, returns Rin to his demon form.

In his human form, Rin does exhibit a number of physical traits that are signs of his demonic nature, which are intensified in his demon form.

In both forms, Rin can control incredibly destructive bright blue flames, a trademark sign of anything related to Satan. However, when he draws Kurikara, the magnitude of the flames dramatically increases and often leads to Rin being "consumed" by his own flames and losing his mind.

Rin also has a Cat Sith familiar, Kuro, which was initially Shiro's.