Josiah

Josiah was an angel from Castiel's faction who killed the angel Ezra, an angel from Metatron's faction who knew about the portal to Heaven, and was thinked to be behind the angels suicide bombing. He was killed by a trap set up by Metatron, being burned by holy oil.

History
When Castiel decided to lead the angels agains Metatron, Josiah was one of the angels who joined him, possessing a man named Sean Flynn, from Omaha, Nebraska. When he disappeared, Castiel and the Winchesters thought he was behind the angel suicide bombing that kill six humans and an angel. For that reason, Castiel and Sam track him down to a Gas-N-Sip in Colorado, where they learn from the store clerk that he was headed to an address in Pray, Montana. When they arrived there, beleaving to have found Metatron's secret portal to Heaven, they found out it was a ruse and find the charred body of Josiah slumped in the corner of the room, having been doused with holy oil and set aflame by a flame thrower above the doorway of an entrance. Josiah surprises Castiel by revealing himself to still be alive, telling after killing Ezra, Metatron told him to come to him and that he would be able to reenter Heaven. When Castiel offers to heal Josiah of his wounds, Josiah refuses telling him he would rather die than owe his life to Castiel. He then succumbs to his injuries and finally dies.