Emperor Palpatine / Darth Sidious
Palpatine is one of those characters that follows wreaking havoc even after death. Because… whether we like the last trilogy of the saga or not, the truth is that the emperor had not said the last word until then.
Palpatine’s main victim is his own master, Darth Plagueis. He drops it himself at the opera while he lures Anakin to the Dark Side. Shortly after, revealing his true face, Darth Sidious would kill three Jedi Masters in one sitting. He also demonstrated his power by throwing lightning bolts from his hands, as well as his ability with a lightsaber.
Objectively speaking, Palpatine is very more powerful than Darth Vader. In fact, according to George Lucas himself, Vader could never be stronger than Palpatine because of his amputations. This does not mean that, in a moment of weakness, Vader finished him off. We could say that he made the same mistake as his teacher.
Luke Skywalker
Despite not having had Force training at as young an age as his father, Luke did prove in the original trilogy to have a power greater than that of Darth Vader. First, because he manages to avoid falling to the Dark Side. And on the other, because he not only manages to defeat him, but also convinces him to come out of the dark.
In the modern trilogy, Luke’s powers are in another dimension. He can even fight on a front, thousands of light years away, on a different planet. Some of his power ends up developing the moment he dies, when he becomes a Force spirit.
Yoda
This lovable old man not only had impressive strength skills, but also harnessed it to form generations and generations of new Jedi.
In Episode III, Yoda is the first to go after Palpatine to stop him. In fact, his wisdom is more than enough to read all the plans of the future emperor. Yoda even refers to him at the time as Darth Sidious.
Although Yoda was not at that time in a formidable physical form, the great teacher faces the Sith and does not make it easy for him. The confrontation is in tables: Palpatine disappears and Yoda gets into the electricity pipes to warn the rest of the Jedi.
Tenebrae / Darth Vitiate
He had mastered the Force since he was a child. In fact, for him, it was like a toy. At ten years old, he was able wresting the power of the Force from his own father. Once turned into Darth Tenebrae, this Sith could use others as if they were puppets. For that reason, he bequeathed himself to become a Sith Emperor of the Old Republic.
The father
This character was developed in depth in Star Wars: The Clone Wars. She was a descendant of the Celestials, and her mission was balance the Light Side and the Dark Side of the Force.
The Father can freely teleport around the galaxy. He can strip his children from their bodies, erase memories, and even stop a lightsaber with his bare hands.