Post in the anime section, or die.
The story revolves arround Rin Okumura, a teenager posessing abnormal strength and endurance who was raised by Father Shiro Fujimoto along his younger twin brother Yukio. Soon after Yukio departs to study at the prestigious True Cross Academy, Rin learns that both him and his brother are sons of Satan, the most powerful of all demons. Witnessing Shiro dying to protect him, Rin ends up doing what his guardian asked him to never do, draw the demon-slaying blade Kurikara that restrains his demonic powers, from its scabbard. From that moment on, Rin not only gains permanent demonic features like fangs, pointed ears and a tail, but also the power to ignite himself into blue flames that can destroy anything it touches.
Of all of the newer animes, this is probably one of my favorites. The idea of exorcism being an actual job that you can "major" in and the entire hierarchy of the organization is really cool imo. The main characters are really likable and its enjoyable to watch them interact and bicker. Although the general plot has been used before (revenge) its done in a different sort of way that makes it fresh