Ao no Exorcist

 A sort of classic that I finally got to watch with Noshi on Netflix, and known in english as Blue Exorcist.

Counting two dozen episodes, this series from 2011 follows Rin, the son of Satan born in the human world.

At age 15, after being bullied, his powers start to awaken.  Astaroth finds him and wants to take him out, but his adoptive father, head of a group of exorcist priests, sacrifices himself to prevent him being dragged to Gehenna by Satan.  Together with his twin brother Yukio, he enrolls in college, and an excorsist school.  His amazement is immense when it turns out Yukio is actually one of his teachers, always having known his secret and being trained in the ways of excorcists since a young age.

He asks Rin along to hunt a lowly demon and save the girl Schiemi, who infatuated by Yukio also joins the class.  During a class camp, they get attacked but it turns out all to have been a hidden test to see if they can become ExWire ranks... or was it, as it seems the director is involved in a plot to bring out Rin's true heritage.

One day, during a training mission in an empty amusement park, Rin is attacked by Amaimon.  The brother of headmaster Mephistoteles, this also forces the hand of one of his mysterious classmates, who turns out to be an inspector send by the Vatican, Shura, and who will train Rin as a promise to his late father.

During their training outings, he learns he has friends that can help him out, but then he is forced to reveal his powers as Amaimon takes Schiemi.  Being brought to trial by the new paladin, Arthur Augustus Angel, he is never the less ruled to become a weapon in the grigori's fight against Satan.  But this all causes distrust amongst his classmates, until one of them gets possessed by a demon and Rin comes to his rescue.

Yukio gets to meet his grandfather, and together they take over the Vatican from the Grigori, as Yukio is sold on his plan to make both the human and the demonworld one and into harmony.  They want to open the gate to Gehenna, upon which the Messiah, a sort of holy nuclear bomb would be tossed in.  But as their grandfather wants to sacrifice Rin for this, the truth gets revealed what really happened 15 years ago and how the boys came to the world, as satan possesses Yukio, in the progress awakening his powers, and making the siblings face off against each other.

So yeah, it was an enjoyable series, even though not one usually "up my genre alley" but with some great laughs along the way.  It's worth checking out for sure, though for me it won't be one of my "waaaawwww awesome" series to remain though...