Circle of reincarnation

The Circle of Reincarnation is a system put in place by Satan and Chimeros, when the peace was signed between angels and demons.

It says that when a demon or an angle is killed in the Middle Realm, they are reincarnated in their respective capital (Eden for angels and Pandaemonium for demons) in a time line depending on their power.

Trivia

 * The most known case of reincarnation is Jesus, who came back to life on Earth after three days in the Ether. This was an evidence of his power, seeing as most high ranked angels or demons tak almost a month to be reincarnated, and low level beings take up to a year to be recreated.
 * Ross Black is the only known human to have been corrupted enough to be in the circle of reincarnation. When Rei killed him, he was reincarnated a month and a half after.
 * Banishing a being to the Abyss or the Dimensional Graveyard removes them from the Circle of Reincarnation.