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 was leading the angels against the Nephilim threat, however it is unclear whether he was the ruler or not.

Lucifer claims to have seen God make angels and that he himself can make new ones. Due to their low population, the angels agreed for him to be the undisputed ruler if he creates more and potentially restores their wings. Later however, he admits to Anael that he lied, and that he is not capable of doing so, having lied just to gain the angels acceptance. He decides it would be better to use his time to find his son and rule Heaven with him.

Eventually, Lucifer absconds from his position, leaving Heaven without a ruler once more. When Castiel arrives in Heaven, Naomi is in charge of the very few angels remaining, but without an archangel such as Gabriel, Heaven will soon crumble and the angels will burn out and die.

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 had begun relying on collective work. There was no clear ruler and all the angels appeared to join together to make decisions.

Lucifer soon took power over Heaven while also ruling Hell but only held the title for one day as he was captured by The Darkness. He took control again by using promises of healing the angels' wings and restoring their numbers but this was merely a lie. He later abandons the position without hesitation.

Following Lucifer's departure, Naomi took over, possibly because she was the highest-ranking and most powerful angel left of the very few who remained. Naomi's function as the Ruler of Heaven was simply trying to keep it going for as long as she could until Gabriel could be found and brought back to stabilize the situation or the angels burned out and Heaven crumbled.

Known Rulers of Heaven

 * God
 * Michael
 * Raphael
 * Castiel
 * Metatron
 * Hannah
 * Lucifer
 * Naomi

Trivia

 * Naomi was one of the many faction leaders in Heaven and one of the most prominent. After Lucifer absconded from his position, she took command of the very few angels left alive in Heaven.
 * 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 whom lost his position 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 during their brief reigns.
 * Lucifer unlike Castiel regained control of Heaven as of Devil's Bargain and with a different vessel. However as of Funeralia it's revealed that Lucifer left Heaven abandoning his post leaving Heaven in control of Naomi
 * Every Ruler of Heaven except Hannah and Naomi 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".
 * Lucifer implies that Duma may have been in charge before he takes over again in Devil's Bargain. This is unconfirmed, but Duma clearly holds a position of power amongst the angels.
 * Every Archangel except Gabriel has ruled Heaven at one point or another.
 * Of the known rulers, most are currently dead or have been presumed dead at some point by at least one person. Only Michael doesn't fall into this category.
 * God was presumed dead by Raphael as shown in Free To Be You and Me because of his long absence. This was disproven when he secretly helped in the Apocalypse and returned to Earth to fight his sister.
 * Naomi was believed dead following Sacrifice until her return in Funeralia. She was also believed to be the Ruler of Heaven before her "death" before Metatron corrected this assumption.
 * Raphael was killed by the Purgatory souls-powered Castiel.
 * Castiel has died and been resurrected multiple times.
 * Hannah was killed by Efram.
 * Metatron was killed by the Darkness.
 * Lucifer was killed by Dean Winchester while he was powered by by the Apocalypse World Michael who he was acting as a vessel to.