My sister made this AU that I thought was neat and I'm gonna share it here
Basically, she found out that Libber was supposed to be in prime empire but they scrapped that idea so she came up with the idea that Libber was trapped in the game only found out Jay was in the game after he released everyone.
The problem is that Libber never managed to get out and with Unagami leaving the game, there was no one to power it. The files and stuff were still there but everything was empty.
For the entire season I guess Libber was being held in a prison cell, maybe being held captive as a backup incase something went wrong with powering the game or smth.
After Unagami left, she was able to escape and was wandering around the place when she spots a poster for Superstar Rockin' Jay and the first thing that comes to mind is that Jay was here and she didn't have the chance to see him.
She assumes that he has something to do with the place being abandoned and gets blinded by her emotions that she wasn't there to help him and wasn't there for him at all really.
So she finds a way to repower the game, hoping to lure him back.
That's all my sister has figured out and I know I didn't word that in the best way but I'm hoping you understand what I'm trying say