Uriel vs War

"Seven thousand years ago, Heaven waged war against all other realms," Lady Hao told Elliot. "Of course, given the fact that an Angel warrior is a combined power of at least three warriors of the other realms combined, Heaven won without breaking a single sweat."

It was because of this era that the idea that the Almighty resided above Heaven was put into place. Heaven monopolized the control of all the realms and they became the center of everything.

It all changed when a man gathered a small group of people and started revolution. He led the entire revolt and usurped Heaven by sealing the realm away from the rest of the realms.

He was successful, and for the past seven thousand years, there has been little to no signs of Heaven's contact to any realm. 

Lady Hao finished. "Even Malice is afraid of Heaven. The ruler of Heaven, the King, can obliterate Hell in a single attack or so the records said."