Palpatine also never considered Maul a direct threat to his life (a one-sided battle between him and Maul in the Clone Wars series shows just how strong the Emperor is compared to his once-apprentice), and simply lost interest in him as time passed - proving how little Palpatine cared for anyone other than himself.
In fact, in this same scene, Sidious says he is keeping Maul alive because he has "other uses for you!" If Palpatine thought Maul knew he about his double identity, there's no way he would have let him stay alive.
After a lightsaber duel against Maul and Savage, Sidious easily kills the latter, enraging Maul, who briefly holds his own against Sidious, but is ultimately defeated. Sidious proceeds to torture Maul with Force lightning, but spares his life because he has other uses for him.
Palpatine did discover Darth Maul had survived before taking Anakin as his new apprentice. In Star Wars the Clone Wars, Darth Maul was discovered by Count Dooku/Darth Tyranus's ex aprentice Savage Opress, who happened to be from the same clan as Darth Maul.
Maul and the Mandalorians make their way down the mountain, via zipline, that the Spire sits upon and escape aboard a Gauntlet fighter. Separatist forces, led by General Grievous, pursue the ship, while Dooku makes it clear that Maul is not to be killed, only weakened. That way, he can seek out Mother Talzin for help.
He does however admit that he had a connection to Maul, probably even more than he did with Vader. He tells Vader that Maul was a true loss when he believed him to have been killed on Naboo. He also feels an anger towards Plagueis when he downplays Maul's significance in the Sith's grand plan.
He even revealed Palpatine's plan to Ahsoka at the end of The Clone Wars, but she refused to believe him. So Maul knew if he outed Palpatine, all he would do is bring the wrath of his former master upon him -- something he wanted to avoid at all costs.
Darth Maul feared Vader in the same way as anyone would. Vader was the most notorious and ruthless figure in the Empire, using his rage and anguish to fuel his resolve, enabling him to dispatch his enemies without compassion or remorse.
Star Wars Rebels lead creator Dave Filoni even admitted that Maul and Vader were meant to have a fight, but he felt it would take away from the battle with Ahsoka. But as things stand, Star Wars not only lacks a fight between Vader and Maul, but the two have never even spoken to each other.
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.
Conclusion. Since that unfortunate day on Naboo, Maul hated Obi-Wan for sending him into a life of suffering and disappointment. Maul spent years plotting his revenge and was able to get a portion of it by killing Duchess Satine in front of Obi-Wan.
Why did Maul die so easily in Rebels, and what killed him? Obi-Wan was the superior duelist in terms of skill. And Maul was tired, mentally unstable, and essentially at the end of his rope.
He also knew that Anakin had been corrupted by the dark side of the Force, and he wanted to spare him from any further suffering or guilt. By not saying anything when Anakin was about to execute him, Count Dooku showed mercy towards his former apprentice and allowed himself to pass away with dignity.
Dooku obviously knows this is real. He's aware that Darth Sidious is a Sith Lord and knows Darth Maul is out there doing the dirty work of Sidious.
He fell under the influence of Supreme Chancellor Palpatine of Naboo, and left the Jedi Order. After learning that Palpatine was secretly the Sith Lord Darth Sidious, Dooku turned to the dark side and became a Dark Lord of the Sith himself, replacing Darth Maul as Sidious's second apprentice.
Yes. He definitely was furious at Maul for what he did to his former Padawan and it really is much more important than people realise. It's possible that Qui-Gon's death was the reason the Clone Wars happened.
1 Darth Sidious
As well as being a gifted bladesman Sidious' connection to the Dark Side is extremely powerful, granting Sidious the ability to conduct force lightning.
Anakin would stomp. The fact that Ahsoka was even able to contend against Maul just goes to show how much Anakin would've obliterated him.
Despite learning that his Master took a new apprentice, Darth Tyranus, Maul still believed that he was a Sith Lord.
Darth Maul Almost Killed Anakin In The Phantom Menace
Maul could have run over Anakin with his speeder or even hit the Chosen One with a lightsaber, something that was only avoided because Qui-Gon warned Anakin to get down. That said, Darth Maul was probably not aware of how important the boy was.
Darth Vader feared his Master. The Sith lord who held his leash and the power to cause him unimaginable pain on a whim. The man who called him “My Old Friend” as a reminder that they were nothing of the sort.
Maul has a classic case of antisocial personality disorder, which is an umbrella term for a sociopath and Psychopath. In order to be labeled this, you need to meet a few criteria. Traits possessed by Maul will be in bold. Tend to be angry, bored, or have a general discontent with their situation.
Sidious replaced Maul with Darth Tyranus, a former Jedi who turned to the dark side. Although Maul survived his battle with Padawan Obi-Wan Kenobi, Sidious moved on with the Grand Plan and replaced him by taking a new apprentice, Darth Tyranus, through whom he shaped the Confederacy of Independent Systems.
So therefore, Maul has received the knowledge and training to be considered Sith, but by being discarded and replaced (as Sidious says in Clone wars) he's not the apprentice and therefore, not part of the Sith or their rule of two. Maul goes his own way and works against Sidious and his empire.
With Anakin out of the picture, thanks to an Ahsoka and Maul team-up at the end of Clone Wars, the attack on the Jedi temple and the mission to eliminate the Separatist leaders would not have gone as they did. Instead, Palpatine would find himself isolated after Order 66 and would have only the clone army to rely on.