Insein
Footballguy
Desperation for the familiar.He's a solid character, so it's understandable why they brought him back.
Supposedly JJ worked with Lucas before even starting E9 and had Matt Smith set to be the villain based on a clone wars plot line. He was going to be the Son of Mortis returned to exact revenge on the Skywalker family. This would have also helped explain the ending better than what actually happened out of no where.
However, insiders said that Iger and Kennedy overruled this because they said they wanted something known that could be marketed to drive interest in Star Wars again after the TLJ failure. Hence they brought back Palpatine.
https://starwars.fandom.com/wiki/Dagger_of_Mortis