All souls are bound to the Creator. When one departs from the world of the living, they end up at the Dark Meridian. When souls are arrive, they come face to face with the creator. Diz is what they call him, but his true identity is Ansem the Wise.
When a soul arrive to Ansem the Wise, they are presented with two choices. A door made of pure light or a dark filled with utter darkness. If a soul in its lifetime was pure they will be allowed to travel into the door of light. The opposite can be said about a soul that was filled with darkness, they will be forced into the door of darkness.
Souls condemned to the door of darkness suffer enternal damnation. Each day they suffer a new form of punishment as retribution for their sins. Souls that enter the door of light are granted a much better life. Depending on how pure they were in their life, they are allowed to become angels.
Once you become an angel, you are tasked with performing good deeds in the world of the living. Once an angel has completed enough good deeds they are able to acheive a higher rank in the angel hierarchy.
Angels are the lowest class of divine beings in the door of light. They are tasked with performing good deeds and govern over the world of the living. After an angel has performed a total of 1000 good deeds, they are able to ascend into the next level of angels.
Archangels are the next class of angels. They possess higher levels of power than angels as well as an extra pair of wings, making the total amount at four. Their task are similar to angels. Since they are more powerful than regular angels they can perform good deeds even faster than regular angels. After an archangel performed 3000 deeds they are allowed to become Ophanim.
Ophanims are the next order of angels. They gain another pair of wings as well, making the total now at six. They are living symbols of Ansem's justice and authority. Their job is to keep order in the world of the living. Without them chaos would reign upon the living world. Once an Ophanim has performed 6000 deeds they are allowed to become Cherubs, the next order of angels.
Cherubs follow in the next hierarchy of angels. With a new rank comes another pair of wings, this making the total at eight. They are known as the protectors. They are tasked with guarding heaven and everyone in it. Since they are the protectors of heaven, they are not allowed to leave. Therefor can't perform deeds in the world of the living. For a Cherub to advance to the next rank in the hierarchy they must have been given their wings by Ansem himself. In order for this to happen, a cherub must have done a total of 9999 good deeds as a Ophanim and trusted by god. This task is acomplished by few, but once a Cherub is able to do so they become Seraphims.
Seraphims are the last and final order of angels. They serve directly under Ansem and possess a total of sixteen wings. They are tasked with caretaking Ansem's throne. Along with that they govern over all other angels within heaven. Originally there was eleven Seraphims in heaven with Ansem. Rikku the heavenly messanger. Aerith the healer. Cloud the almighty second in command in heaven. Cid the 'eyes' of Ansem. Leon the heavenly scribe. Tifa the one that conveys prayers. Zack the one that ends suffering. Yuna the one that bears Ansem's merciful love. Paine the angel of death. Lastly their was Xehanort. Xehanort was given the name 'Morning Star' and was in charge of bestowing light to the world of the living.
Xehanort was once the most beautiful of all other angels. Ansem loved Xehanort the most of all the other angels, even better than Cloud whom was considered Xehanort's older brother and the first Seraphim. Since he was loved by Ansem, he was extremely prideful. After Ansem created mankind and asked the other angels to love his newly created creations, Xehanort refused. Eventually this lead to a rebellion in Heaven. Ansem then ordered Cloud to cast Xehanort out of heaven. Once he fell from grace, he naturally was angry. He struck back by spliting his soul into eleven pieces. Because of his actions, Ansem ordered Cloud to further punish him. Cloud then sealed him into a cage he then called Xehanort's Cage. He then placed a total of 666 seals onto the cage to prevent it from ever being opened again.
The reason Xehanort split his soul into eleven pieces was for as long as his soul was still alive, he could not be killed or destroyed. Those eleven then became the very first demons. Once they came to be, they joined together and formed an organization that one day will revive their fallen creator.
Now all that was left in heaven was only ten Seraphims. Millenias after the downfall of Xehanort, an angel named Sora was created. Sora's only dream was to fill that empty slot in the rank of Seraphim. Sora had already reached Cherub level and had completed 9998 good deeds. He was so close to acheiving his goal.
He had made his way cheerfully to Ansem to recieve his last task. He was outside the gates that lead to Ansem's personally chamber. The gate was pearly white and gave off a radiant shine. Sora was about to knock on the door when he suddenly heared a voice.
"Come in Sora." The voice said.
Sora didn't know what to expect. The doors flew open and inside revealed a man sitting behind a desk.
"Please Sora, come on in." the man said.
Sora did as he was instructed and headed inside. Once he was inside, the man man offered him a seat in a chair and waved his hand, causing the doors to close.
"I know why you are here." the man gently said.
"Really? You do?" Sora asked.
"Well I am godafter all." the man joked.
"It's about my last deed. The one I need to do to ascend to become a Seraphim." Sora told him.
"Yes. You must the first angel to every acheive this task in quite sometime. Well I have the perfect one for you." the man said.
"Really? Do tell." Sora said, sounding intrigued.
"You are to correct what you did wrong in your past life." the man said.
"My past... life? What does that have to do with anything?" Sora asked again.
"The past has to do with everything. In your past life you were the son of a powerful king who was at rivals with a nearby general. You were tasked to seduce the general and spy for your father, the king. After you seduced the general you used your newly founded power to kill millions and hurt thousands." the man answered.
Sora gave no response. He was shocked to hear this as this was the first he ever heard of something like this.
"After you died, you came here. You were originally condemned to spend an eternity in the pits of darkness for your evil deeds but I saw potential in you so I made you an angel." the man said.
"So how do I correct what was wrong?" Sora questioned.
"Here take this pouch. Inside are your instructions." the man said. He waved his hand again and a small golden pouch appeared. On the front was a very stylish looking heart. He then handed it to Sora.
"When the time is right, open it and it will show you the way."
Sora thanked the man and ran off out the door. After he left the man chuckled and closed the doors. Sora was excited about what he just heard and immediatly went into action. He went to the gate that lead to the world of the living and opened them. He jumped on through and manifested his eight shining wings. He then flew towards a small sunny island.