I was looking at some old comments and found this really cool one by Luciferier (I made a few grammar fixes):
I feel like a cool secret class like "Saitama" could be "Stand User" with like a "yare yare daze" description and a Jotaro tipping his hat avatar.
And maybe the way you unlock the class is by defeating the boss, choosing a "go to jail" option or something and then stabbing yourself with a Stand Arrow (not really how Jotaro got his stand but whatever).
Of course the class would have specific abilities (for example Pose -> Stand Punch -> Stand Barrage, and Block -> Stand Block -> Stop Time).
And just like how when you pick "Saitama" your head looks different, if you pick "Stand User" you will have a Jotaro hat on your head.