Castiel

Castiel (/ˌkæstiˈɛl/; nicknamed "Cas")[1] is a fictional character portrayed by Misha Collins on The CW's American fantasy television series Supernatural. An Angel of the Lord, he first appears in the fourth season and is used to introduce the theme of Christian theology to the series. In the series, Castiel brings Dean Winchester back from Hell and frequently helps him and his brother, Sam, in their battles with various demons and angels along the way. During his travels with the Winchesters, Castiel develops friendships with both men. As an angel, he possesses a number of supernatural abilities, including the ability to kill demons.[2] Initially, the character demonstrates complete devotion to God and little emotion. However, his interactions and experiences with Dean and Sam, as well as certain revelations about God and his fellow angels, have a humanizing effect on him. This, despite the stress and harm it causes his character, allows him to develop an independent will as the series progresses and helps the show address topics related to free will.

Unlike the stereotypical portrayal of television angels, Castiel does not always help people, and is willing, at least when he is first introduced, to kill innocents if needed. Collins originally read for the part of a demon, as series creator Eric Kripke did not want fans to find out that angels were being introduced to the series. Collins prepared for the role by reading the Book of Revelation and based his portrayal on his younger brother. Critics and fans have responded highly favorably to the character. In response, the show's creators expanded his role in the series, upgrading him to a main cast member in the fifth and sixth seasons. After being a special guest star in the seventh and eighth seasons, Collins was upgraded once again to regular cast member status through seasons 9–15.[3]

https://en.wikipedia.org/wiki/Castiel_(Supernatural)