Who is the most powerful character in The Witcher? The world of The Witcher is filled with tons of fantastical creatures such as monsters, monster hunters, mages, sorcerers, and all kinds of beings. The Witcher universe is very large and has extended past the books to become a popular video game series, TV show, and even a movie called The Hexer. The Netflix series has given its own unique insights into the strengths of each character, making it more difficult to truly answer the question of who is the strongest of them all.
Based on the Netflix show so far, Yennefer is by far the most powerful character. Later in the series there may be more powerful characters to emerge from the world, but for right now she has not only the strongest powers and abilities shown on screen, but she also has control over them—unlike characters like Ciri. The Battle of Sodden Hill seemed hopeless against the strength and numbers of the Nilfgaard army, that is until Yennefer was able to harness the chaotic energy from the battle and channel it into a devastating attack that wiped out the entire remaining Nilfgaard army—all singlehandedly. Yennefer, in this one act alone, showed more power than any other character on the show, possibly even combined. If it was not for her, the battle would have been lost to the Nilfgaard.
Yennefer has elven blood in her, making her biologically more powerful than others. Although Yennefer may not be as strong in the books as she is in the Netflix series, the show is its own world. And in that world (up to season 1) no other character comes close to Yennefer's abilities. However, actor Cassie Clare has been cast to play a character in season 2 that might rival Yennefer. In the book series, Philippa Eilhart is one of the major antagonists of the story. In the game series, however, she was not featured as heavily. This character is mostly bad but does have a good side with powers that could possibly match or outrank Yennefer somewhere down the storyline. Yennefer is very old and has had many years to train her powers, which is why she is so strong.
Some might say Geralt is the strongest character because he is the main protagonist, after all. He is an accomplished monster hunter whose stories are told across the land through song and tale. In close combat with a sword, no one comes close to Geralt's fighting abilities. As a Witcher, Geralt has some basic magic abilities, superhuman reflexes, and the ability to see in the dark making his job as a monster hunter very profitable. Though he is trained very well with a sword, and he is very strong physically, Yennefer had a higher kill count in season 1 and showed more ability than Geralt. He is definitely one of the most powerful characters on the show, but even just in season 1 he has been outmatched. Even what little of Ciri's powers were shown, they still appeared to be able to produce more damage than anything Geralt did on the show so far.
Vilgefortz is a character viewers saw very little of in season 1, but what was shown of his fighting abilities and powers seemed deadly. Although it is heavily implied that he lost his battle with Cahir, many think the fight was really just for show for Yennefer and others and that he will actually be joining the Nilfgaardian army. At the end of The Battle of Sodden Hill in episode 8, Vilgefortz is seen killing an ally, a moment of betrayal that is supposed to be shocking for the audience. In the books, Vilgefortz is the main antagonist. Should the Netflix show decide to stick to the books, then this character could become one of the most powerful characters in the series, maybe even more powerful than Yennefer. But so far, this villainous character does not appear to be too much of a threat.
Ciri will be heavily featured in season 2 of Netflix's The Witcher, based on the very short teaser trailer released this year. It looks like the show will follow her story a little bit more than it did in the first season. Although she was heavily featured in season 1 as one of the three main protagonists, we really didn't get to see her powers. So season 2 will be more focused on her and will show her training with Geralt to become stronger. When Ciri learns how to gain control of her abilities, she will become one of the most deadly and powerful characters. Season 2 could explore the idea of Ciri being a Source (a person who is a source of great energy and magic) but this sort of power is not easily controllable and acts through a person rather than letting a person wield it. Until she can learn to control herself, she remains a strong character, but not the strongest.