Witches
Bonnie Bennet
Bonnie was one of the main characters and was for sure the main character when it came to the witches on vampire diaries. Her grams would always tell her stories about the women in their family and about how they were witches/ "psychic" but Bonnie never believed it she slowly started tapping into her power and weird events would take place. She eventually tapped fully into her witch power and became very powerful. In the show she died many times but came back every time. Since she was a supernatural being she was on "the otherside" which made it possible to bring her back to life when she would "die."
Liv Parker
Liv parker is part of the Gemini coven, which is known for merging with their twin to see who is stronger once they turn a certain age. Liv's twin is Luke, but she was also the younger sister of Jo Parker and Kai Parker.
Luke Parker
Luke is Liv's twin and is also part of the Gemini coven both Liv and Luke are very powerful witches. In order to save his twin and older sister's life he does the merge with his evil older brother Kai, but he losses.
Jo (Josette) Parker/
Laughlin
Jo ended up escaping her family and hiding her magic in a safe place just in case she ever wanted it back but for the most part she lived a normal life until she met Alaric, Elena, Stefan, and Damon and then later meets her younger siblings. Once her twin Kai escapes the prison world, she has to face him, so she gets her magic back, but she was never the strongest witch, and she didn't care to live that life.
Kai Parker
Kai is Jo's twin and is also part of the Gemini coven, but he is a siphon which means when he touches anything containing magic, he sucks the magic right out of it. He was a very dangerous witch, and his coven locks him in a prison world, he ends up getting out but then Bonnie locks him back into another prison world and he gets out again, but this time becomes a heretic which is a vampire and siphon.
Qetsiyah Bennet
Qetsiyah was the most powerful witch in the show. She created the immortality spell for herself and silas and then created the cure and other side all in the name of revenge once the love of her life Silas betrayed her. Qetsiyah was not in the show the whole time because she was on the other side, but she had the opportunity to come back to the land of the living and she took it. Bonnie Bennet is a descendent of Qetsiyah.
Silas
Silas was the first doppelganger and also a very powerful witch until he convinced Qetsiyah to make the immortality spell and then he betrayed her and used the immortality spell with Amara the other original doppelganger. Silas is not just any witch once he became immortal, he was able to read people's minds and control what they saw, thought, and spoke.