laughs forever

Yusuke legit got kicked off planet in fear of him becoming this.

He would have to be in berserker mode for this to happen and some pretty heavy magic applied.

Xanxes is only Mid Boss.... we was already this.

Jamie is not in fact a Boss at all. He is a minion. He likes being a minion stop trying to MAKE him a Boss damn it and order him around damn it. '

Kurama. Ok Kurama.... yep

Pls Note Yusuke never fought Kurama.

He could easily become Final boss. He may even do so to amuse himself and give Yusuke someone to fight once Yusuke starts flagging in a few centuries.

It would actually be a fucking game.

He Frightens me.

Xander... actually I could see it happening but it would have to be some serious bullshit via Powers that be and magic nonsense.