The "Dragon Ball" franchise has seen characters of different power levels ascending to the top. There was a time when the most powerful character was Goku's brother Raditz, and Goku needed to die to beat him. The most powerful escalated into the likes of Vegeta and Nappa. Well. you know the ascendance drill - Frieza, the numbered androids, Perfect Cell, Buu and his various forms, Beerus, and eventually, Zen-Oh. "Dragon Ball Super" defies logic by escalating various characters to prominence, and eventually reached a promising note that Goku can somehow reach their power levels.
But Zen-Oh is different. He's not just a God, he is the God of all Gods; the God of everything. He is the most powerful character in the franchise right now. But can he be replaced?
Gods of Destruction, Angels, and the Omni-King
Gods of Destruction such as Beerus and Champa are powerful beings that were once mortals. Goku and Vegeta have been candidates for God Of Destruction because of their power, but both have declined the offer. It can be concluded that mortals have a chance to become divine beings through reaching the level of God of Destruction. These Gods are replaceable in nature, though their existence lasts for very long. Having once been mortal, these Gods are also capable of mortal emotions such as anger and rage.
Angels, on the other hand, have to guide the Gods of Destruction in their duties. Training a candidate and attending the current God's needs are the sole purpose of an Angel. If the God they serve dies by any means, they will be inactive until a new God of Destruction appears.
The Great Priest is the exception to the group. Being the most powerful angel and the assistant of the Omni-King, he is the most powerful being beside Zen-Oh himself.
The majority of important matters are handled by the Great Priest, making him the real authority of the whole multiverse, though he can't protest or go against the decisions of Zen-Oh.
Zen-Oh himself is the most powerful of all. He can create things and destroy them in an instant. The Gods of Destruction fear him and even the Angels know what he can do.
It seems like Zen-Oh can never be replaced, can he?
The possibility of replacement
If the parallelism of the situation is observed, Zen-Oh is just like the Gods of Destruction while the Great Priest is just like other angels who serve their Gods. Once the Gods are performing poorly in their jobs, Zen-Oh replaces them. The same could be done to Zen-Oh. Who would do the replacement is not known, but it could possibly be the Great Priest. He could do the duties of the Omni-King until a being powerful enough to take the title of Omni-King appears. It seems that the Grand Priest and the Angels are the only constant things in this multiverse. They carry out the jobs of protector of the multiverse and creating balance to allow civilizations to prosper in a given era.
Frieza aims to be the next Omni-King. If he became powerful enough, he might be able to replace the Omni-King. But if the Grand Priest deems Frieza to be unable to do the job, Frieza will need to defeat the Grand Priest first, or at the very least, Goku or Vegeta.
