2. Darth Vader/Anakin Skywalker
In the prequel trilogy and The Clone Wars animated series, we see just how capable Anakin Skywalker is. He’s skilled with his lightsaber and skilled with using his Force abilities to aid him in battle. Since there was a literal war going on in The Clone Wars, he wasn’t always fighting someone one-on-one.As the show continued on, I could see Anakin leaning more and more towards the dark side, despite all of the good he had done. As he became more powerful, he became more susceptible to giving into the darkness inside him. We see that happen and what comes out of it is Darth Vader.
In the original trilogy, Darth Vader was the one who no one wanted to cross paths with. In Rogue One, the character had a short, but impactful moment on-screen. He was ruthless and until his second fight with Luke Skywalker in Return of the Jedi, he seemed unstoppable. Luke chose to save him when he would have been perfectly justified to let him die.
To take things back a moment, one of the other biggest fights came when Anakin was up against his mentor, Obi-Wan Kenobi in Revenge of the Sith. At that point, Anakin had already killed many Jedi, which meant that Kenobi’s only move was to try to take him out. We all know how it ends, so there’s no need to go over it. Anakin Skywalker is undoubtedly skilled and when he turned into one of the greatest villains ever, we could all see how it happened.