Jimmy enlisted 7 powerful demons and humans to protect his kingdom and followers. They were first mentioned in Episode 13 when Gouki was first introduced. Their number doesn't mean to match with their power status, they are simply just a number.
List of Warlords
Deceased/left on their own accord
Pepe: Left after exposed to Jimmy's true intentions.
Feels/Wojak: Followed Pepe.
Rook Blonko: Quit on his own accord to run a successful meme page on Facebook.
Crocodile: Came out as Transgender.