1. Emperor Palpatine. Darth Sidious infiltrated the heart of the Republic and twisted it into the Empire, sparked a terrible war that engulfed the entire galaxy in fire and ash, corrupted once-noble Jedi to his cause, and executed Order 66 to erase the Jedi Order from existence.
Sheev Palpatine was often considered the embodiment of evil and Star Wars' main antagonist.
Anakin Skywalker, aka Darth Vader, is no doubt the most famous Jedi who turned evil in the Star Wars Universe.
1 Darth Sidious
There has been no Sith, as powerful, meticulous, nor as evil as the Emperor himself, Darth Sidious. As previously mentioned, Sidious trained in the Dark Side by Darth Plagueis before Sidious killed Plagueis in his sleep, making Sidious a Sith Master.
Plo Koon. Wise and compassionate, Plo Koon was one of the most effective Jedi masters, genuinely caring about the clones he commanded.
Dark Jedi, also known as "Fallen" Jedi, were Force-sensitives, frequently former Jedi, who chose to deny the light side of the Force or follow the dark side.
In the original trilogy, Palpatine is depicted as the Emperor of the Galactic Empire and the master of Darth Vader (Anakin Skywalker).
Although the decision to turn to the Dark Side was Anakin's alone, the choice did not come from thin air. His natural prone to impulsivity and emotion without the support systems he needed in place made it easier for Anakin to stumble down a path of darkness.
During the Battle of Endor in 4 ABY, Sidious was killed by a redeemed Anakin Skywalker, who turned back to the light side of the Force and threw Sidious down a reactor shaft to save his son Luke Skywalker.
In the film's climax, Maul duels Qui-Gon and his apprentice Obi-Wan Kenobi (Ewan McGregor). He is able to kill Qui-Gon and knock Obi-Wan down a shaft, but Kenobi propels himself out of the pit and uses Qui-Gon's lightsaber to bisect Maul, sending the two parts of his body falling down the shaft.
In the original Star Wars trilogy, Luke Skywalker represents the hero archetype of "the young man, called to adventure, the hero going out facing the trials and ordeals, and coming back after his victory with a boon for the community".
The Conclave of Katarr was the assembly point for many Jedi, who underestimated the power of Nihilus. When he consumed the life of the entire planet, almost all the 100 Jedi that were gathered there lost their lives.
The clear answer for the smartest Jedi of them all is Master Yoda. This mysterious but beloved character comes from a species about which very little is known, and has survived through many eras, stretching back to the High Republic.
What Padmé knew about Anakin's previous dark deeds. Padmé was well aware that Anakin had committed dark crimes that would've started his fall to the dark side. He even confessed to her that he had massacred an entire Tusken Raider village to avenge his mother, leaving no one alive.
The final season of The Clone Wars reveals that freaking Darth Maul was aware that Anakin Skywalker would directly lead to the downfall fo the Jedi and the destruction of the Republic.
But Star Wars: Darth Vader #26 reveals that Anakin's hatred of sand doesn't simply come from his life on a desert planet, but from an intense, traumatic moment involving his mother and a near-death experience.
Darth Vader lost his left arm and both legs when Obi-Wan Kenobi defeated him on Mustafar. After turning to the dark side of the Force, Skywalker severed Mace Windu's right hand to save Darth Sidious when Windu tried to kill the latter.
Introduced in the first film in the original Star Wars trilogy, Governor Tarkin is the Grand Moff of the Galactic Empire and commander of the Death Star.
In Star Wars Canon, only Luke Skywalker can be acknowledged as the one who truly defeated Darth Vader.
It was Barriss herself who orchestrated the bombing and framed Ahsoka. Anakin dueled Barriss on Coruscant, and eventually placed her under arrest. Brought before a military tribunal led by Governor Tarkin, she admitted her guilt, but held steadfast in her belief that the Jedi and Republic had lost their way.
The Jedi were trained to accept death as a natural part of life and to let go of everything they feared to lose. The Jedi Code stated that "there was no death," only the Force.
Jedi Master Adi Gallia was a member of the Order's High Council during the Clone Wars.