Darth Maul could have killed Anakin Skywalker at least twice and therefore prevented Darth Vader from being created, but that does not mean he would have been powerful enough to stop Darth Sidious' rise to power.
Yep. Darth Maul didn't really say or show straight up that he "feared" Darth Vader, but he openly stated his belief that he could not defeat Darth Vader without the help of the Jedi, therefore on his own.
And while his warnings don't work, at the very least, it shows that Maul became aware of Anakin and what he would soon become. With the rise of the Empire, it's likely Maul caught on to Vader's existence pretty quickly.
Thought dead, Darth Maul survived his injuries by focusing on his hatred of Obi-Wan Kenobi, the Jedi who cut him in half. His shattered body was dumped amid the refuse of the junk planet Lotho Minor, where the once deadly warrior fell into madness, staying alive on a diet of vermin.
What would have happened if Darth Maul killed Obi-Wan?
In this scenario, Maul would cause Luke Skywalker to fall to the dark side and then begin training him as an unofficial Sith. With Obi-Wan Kenobi dead, Maul's thirst for revenge wouldn't end, and he'd set his sights on a more dangerous opponent.
What if Anakin Went to Mandalore to Fight Maul- Star Wars Theory (Scenario 1)
Why was Obi-Wan sad when Maul died?
When he dies in Rebels you see Obi-wan holding the dying body of Maul. This is supposed to represent that he's gone beyond hatred or anger towards Maul, and instead feel pity that it had to end this way.
He'd still have to watch over Luke, but he'd also be free to start a life together with Satine. One could conclude that she would reject his lifestyle as a hermit on Tattooine, so he may have been forced to choose between protecting the Jedi's last hope and the woman he loved.
Sidious revealed to Maul that he did not intend to kill his former apprentice, as he still had use for Maul; it was Sidious' hope that Maul would lead the Sith to Mother Talzin, Maul's mother and the leader of the Nightsisters, so she could be eliminated as a potential threat to the eventual Sith rule of the galaxy.
Though he killed Jinn, Maul was, in turn, defeated by Kenobi, who bisected the Sith assassin at the waist. Darth Maul was believed to be dead in the aftermath of the battle but ultimately survived, emerging a decade after his defeat, during the height of the Clone Wars.
Maul most likely knew Sidious' double role as Palpatine and Sidious when he served as Palpatine's apprentice. He definitely knew about Palpatine's goal of creating a galactic empire ruled by the Sith. Maul knows that Sidious is the Emperor.
R2-D2 was present when Padmé gave birth to Leia and Luke, so he knew Luke was Anakin's son – but what he didn't know was that Anakin became Darth Vader. In addition to that, Anakin's fall was surely a painful event in R2-D2's life, one that he definitely wouldn't like to remember or even talk about.
Plagueis, however, was fully aware of Maul's existence, and supported Sidious's decision to train him. The primary reason for Plagueis's support, despite the violation of the Rule of Two, was that Maul was trained to be expendable.
By the time of Episode 3; Anakin is in his prime, and already one of the Jedi Order's most powerful “masters” (although technically still a knight), just behind Obi-Wan, Windu, and Yoda. Maul wouldn't stand a chance. Anakin stomps.
As the son of Mother Talzin, the Zabrak male was taken from a young age by Sidious to act as his impressionable apprentice. The boy was raised as Darth Maul, a name he carried throughout his life. In Legends, it was insinuated that he was born "Maul" before attaining the honor of the "Darth" title.
Per canon in the titular story within From a Certain Point of View: Return of the Jedi, Obi-Wan, like the true Jedi he was, gave Maul a proper cremation according to Jedi customs before Order 66.
The two were able to free Maul after he had been interrogated by the Sith Lord Count Dooku, and together the three rendezvoused with more Death Watch forces on the moon of Zanbar. Maul took command of his forces once again, and assured them that the war they had longed for was at hand.
He regretted it because he had essentially wasted 20 years training him. But since he was an enemy at the time of his death on Tatooine, Sid was glad that he did not have to keep watching his back anymore now that the loose ends were tied off.
Maul's skills, on the other hand, became stagnant as he spent the last few decades of his life keeping himself alive and plotting schemes. Given this, it makes sense Obi-Wan quickly defeated Maul in their final duel in Star Wars Rebels.
To say he is tragic is an understatement. He is far too sympathetic to be Pure Evil or Near Pure Evil for the following reasons: Darth Sidious stole him from his biological family on Dathomir and then groomed him into a living weapon through years of excruciating physical and mental training.
Maul confirmed to be written out of Kenobi series :( Apparently Ray Park was on set for pre production but was cut out after script was rewritten. I somewhat get they want to limit fan service and nostalgia by adding to Inquisitor story arc but at least include Obi-Wans mortal enemy in his own show.
