Out of all the Star Wars movies, one of the scariest villains ever has to be Darth Maul, who only appeared in The Phantom Menace. His red face, piercing yellow eyes, black face tattoos, and horns certainly make him the most creepy looking Sith Lord. And based on what happened to Darth Maul in The Phantom Menace, he also may be the most hated Star Wars characters as well.
That's not just because of the fact that many people agree that Episodes I-III are weaker than the other Star Wars movies, of course. It's due to the fact that Darth Maul (Ray Park) killed the beloved character, Qui-Gon Jinn (Liam Neeson). Well, kind of. In an intense fight scene towards the end of the movie, Darth Maul pushes Obi-Wan off the ledge, then kicks Jedi's lightsaber off as well. It seems like Obi-Wan (Ewan McGregor) is doomed to die with Qui-Gon in the chamber. In a valiant show of Jedi willpower, however, Obi-Wan uses the Force to levitate back onto the platform and uses Qui-Gon's lightsaber to sever Darth Maul in half. The Sith Lord falls off the platform and audiences see his body split in two.
As gory as Darth Maul's final scene may be, you probably won't find many who felt very bad about it considering Qui-Gon died first — well, again, kind of, because Qui-Gon did die in Phantom Menace, but Yoda hears the Jedi Master's voice both in 2002's Attack of the Clones and a deleted scene from Revenge of the Sith as a Force Ghost.
Darth Maul's murdering of Qui-Gon indirectly led to Obi-Wan later training Anakin Skywalker, the Chosen One, to become a Jedi Master. That's because as Qui-Gon died in Obi-Wan's arms, he made the latter promise to train Anakin. "He is the Chosen One, he will bring balance. Train him," Qui-Gon said. Had Darth Maul not killed Qui-Gon, the Jedi Master who had saved Anakin from slavery in The Phantom Menace would have trained Anakin himself. Who knows what would have happened if that were the case — Anakin probably would have still turned into Darth Vader, but you really never know.
Even though Darth Maul had a great impact on the series of events in Star Wars by indirectly leading Obi-Wan to train Anakin, he still had a minor role in the films altogether. As an assassin, Darth Maul always worked for Darth Sidious, aka Senator Palpatine. Darth Maul first started out as Plapatine's apprentice, and then he took on the assignment to kill Qui-Gon, Obi-Wan, and to capture Queen Padmé Amidala (Natalie Portman). In his first attempt to capture Queen Amidala, Darth Maul had a run-in with Qui-Gon on Tatooine.
During the first duel that took place between Darth Maul and Qui-Gon, the former showcased peculiar Jedi skills for someone supposedly untrained in the Force's arts. That fight led Qui-Gon to discover that the Order of the Sith Lords had returned, which the Jedi had previously thought were extinct. Again, Darth Maul played an integral role in the overall storyline of the Star Wars prequels, without having many speaking lines. In fact, Star Wars' Wookiepedia states that Darth Maul only had three lines throughout the entirety of The Phantom Menace. Apparently you don't need to say much when you look like what many people might picture when they try to imagine what the devil looks like.
Even if you can't forgive Darth Maul for making Liam Neeson's Star Wars role last for only one movie, you have to admit, the Sith Lord had a great influence on the series. Without him, Obi-Wan may not have trained Anakin to become a Jedi and then later Luke Skywalker. If not for that, Luke Skywalker would not have trained Ben Solo, who later became Kylo Ren in the newest Star Wars series, and basically, Darth Maul is the reason for Rey. Whether or not you'd like to thank him for his work is up to you.