I’m not much of a fan of the ROTJ Emperor either. It is very clear that he was set up to be far more of a threat than he ended up becoming, what with condensing the sequel trilogy plot into the third act of the OT. That’s why in my version of ROTJ, the Emperor is just an insane clone of Palpatine who’s been led to believe that he’s the real deal and sent to that Death Star to lure the Rebels into a trap. The real Palpatine is safely on Coruscant this whole time drinking thousand-year-old wine and chuckling quietly to himself.