Ruler of Heaven

The Ruler of Heaven is the leader of Heaven's angels.

History
Since the creation of Heaven and its angels, God ruled Heaven from his throne room. After Lucifer bypassed Gadreel's defenses and corrupted mankind, God ordered Lucifer's imprisonment and then left.

Michael, being the most powerful archangel, became viceroy over all of Heaven, but did not reveal God's absence to the majority of his brethren. He ordered the angels to stay away from humans for 2,000 years, after which he and the senior angels worked to get the Apocalypse going.

Michael's defeat and fall into the Cage caused Heaven to lose stability. Raphael, the only archangel available at the time, sought to become the new leader with his first goal being the restarting of the Apocalypse.

Castiel defied Raphael and a civil war broke out. Through the power of 30-40 million monster souls and the Leviathans, Castiel was able to obliterate Raphael and any who opposed him. His death at the hands of the Leviathans left Heaven without a proper ruler.

As a result, many factions were formed, each seeking to take control over Heaven according to their own will. Among them was Naomi. Metatron was able to kill Naomi and banish all the angels from Heaven, declaring himself the new ruler.

The combined efforts of Castiel and Gadreel resulted in Metatron's defeat and imprisonment. Heaven subsequently voted Hannah as the next ruler, though it is unknown how much power she possessed. After a while, Lucifer claimed the throne of Heaven in order to unite all the angels against The Darkness.

Following the battle's conclusion, Heaven was left, once again, without an established ruler, as God had departed from Earth and Lucifer had chosen to rule neither Hell nor Heaven. In Somewhere Between Heaven and Hell, the angel Kelvin indicated that Joshua took up this position. His position was short-lived however.

Characteristics
The Ruler of Heaven has complete authority over all the angels. God, as the creator of Heaven and its angels, is the most eligible candidate for the position. In God's absence, the most powerful angel is next in line to take the throne, though the angels can also elect whomever they choose, as in the case with Hannah.

When the angels cannot immediately decide who should rule Heaven, many individual angels will rise up to make claim by forming their own faction and try to exterminate their rivals. When only two sides stand out, this can lead to Civil War.

Following Hannah's death, the angels have begun relying on collective work. There is no clear ruler and all the angels appear to join together to make decisions. At some point, Joshua decided to take command himself. His death however, left Heaven without a leader once again.

Known Rulers of Heaven

 * God (since creating it until Lucifer tricked Gadreel and then he left)
 * Michael (Since God left it - 5; imprisoned in Lucifer's Cage)
 * Raphael (6; deceased)
 * Castiel (7; for a short time)
 * Metatron (9; overthrown)
 * Hannah (10 - 11; deceased)
 * Lucifer (11; for a short time)
 * Joshua (12; deceased)

Trivia

 * Many people think Hester led Heaven after Castiel, but this was never proven.
 * Naomi was one of the many faction leaders in Heaven and one of the most prominent.
 * While Hannah took over Heaven after Castiel and Metatron it was never really cleared how much authority she had, especially after one of her angels killed her.
 * Presumably, Heaven is self-operated by all the angels, as together they were able to plan the first combined smite against Amara, and make the decision to lock themselves up once they deemed God was dying.
 * This self-operation was briefly disrupted by Lucifer and Joshua, both of whom lost their positions shortly after.
 * An unnamed angel briefly took charge of Heaven following Hannah's death, and commanded the angels to lead the first assault on Amara in "O Brother, Where Art Thou?". Whether he can be considered a Ruler of Heaven is unclear.
 * Two of Heaven's Rulers, Castiel and Lucifer have both been portrayed by Misha Collins.
 * Every Ruler of Heaven except Hannah and Joshua has met God at one point in their lives.
 * Hell and Heaven shared a ruler only once in 2016, when Lucifer took charge of both. This period lasted for about a day.
 * Metatron is the only ruler to completely rename himself, calling himself "X".
 * Castiel and Lucifer, during their brief rule, called themselves "God".