D. Gray-man

Allen Walker is a boy with something unique. It is known as a Cursed Eye. He uses it to identify monsters known as Akuma. Akuma are monsters that were created by using the souls of the dead. Akuma are so deeply affected by their sorrows that they become violent and destroy humans. An evil being known as the Millennium Earl is responsible for the creation of these monsters. Allen uses a special weapon known as an anti-Akuma weapon to defeat these Akuma and save their souls. After discovering his powers, he decides to become an Exorcist; a person with an anti-Akuma weapon that works for a special force known as The Black Order. The Black Order's purpose is to obtain Innocence; a powerful substance. They also destroy Akuma with their weapons. After being accepted into the Order after having quite an argument with a soon-to-be working partner named Kanda, Allen meets Lena Lee. He befriends many, and his long journey as an exorcist begins.

D. Gray-man seems like a teen-adult show because of the fact that some of the Akumas are pretty scary, blood, and there is some colorful language. My overall opinion about the show can be described in on e word: epic.