Malachi (Supernatural)

Malachi is a fallen angel who appears as a supporting antagonist in season 9, he is a rival of Bartolomew.

History
Malachi was very much of the angels that fell into Heaven due to Metatron's spell. After his fall, he made a fiction of angels to kill those who refused to join him. Malachi angry with Castiel and because his grace is stolen, unknowingly playing a key role in Metatron's spell. And during that time, he started a rivalry with Bartolomew, he killed Bartolomew's angels with the help of his angels, just like Bartolomew, Malachi also wanted to overthrow Metatron. Malachi later joined the meeting with Bartolomew's representatives and both agreed that they wanted to overthrow Metatron. However Malachi felt disrespected when Bartolomew did not come to the meeting and both turned against each other and started a war that would rule Heaven.

During this time, Malachi manages to capture Castiel who was in a motel while he followed the angel who visited him. Malachi killed that angel. While torturing Castiel and interrogating Castiel about Metatron's spell. But later Castiel breaks free and steals the angel's grace and kills him. Malachi is then revealed to be killed by Gadreel under Metatron.