In Revenge of the Sith, what if Anakin had decided to stay at the Jedi Temple while Palpatine was arrested?
After being disarmed, Palpatine goes through all the same motions: “I can’t hold on any longer,” “I’m too weak,” “Please don’t kill me,” and other things to make him seem defenseless. But, like in the movie, Mace ignores them and decides to kill Darth Sidious right then and there. Darth Sidious lets him, because OOPS Mace just killed the lord of the Sith in an act of anger! You see, I believe this was the backup plan all along. The sacrifice is complete; the Sith Lords now possess the body of one of the strongest Jedi Masters currently living.
“Mace Windu” returns to the Jedi Temple and tells Anakin the following story: Palpatine confessed immediately to consorting with the Sith, but denied being - or knowing the true identity of - Darth Sidious, before being placed under house arrest under the supervision of three Jedi (Tin, Fisto, and Kolar - the three Jedi that were just killed in combat). Hours later, the bodies of Palpatine and the three Jedi are discovered, along with doctored security footage showing a cloaked figure killing them.
From this, the story that gets reported is that Palpatine was privately working to investigate the Sith, but was assassinated by them before he could expose their secrets. He was already popular, and now he’s a martyr. As suggested, the Jedi Council is forced to take control of the senate in order to secure a peaceful transition. At the same time as all this, Commander Gree is ordered to kill Yoda, and because no other Jedi have died, Yoda is unable to sense the danger and is successfully assassinated (Everyone is told he died in battle). So-called “Mace Windu” is now head of the Senate AND Jedi Grand Master. Obi-Wan is sent to Mustafar to negotiate with the Seperatist leaders, but the whole thing is blown up with him inside. The two greatest threats to Palpatine have now been eliminated.
But with the Jedi now the seat of Palpatine’s power, whom can he use as a scapegoat to explain the assassinations? Crimson Dawn. He has the republic army find and kill Darth Maul, and everyone is told that Maul was the Sith master behind the whole thing. In this timeline, this is the “attempted coup” used to justify forming a Galactic Empire. Padme, disgusted, resigns from the Senate.
Before Anakin can begin asking too many questions, “Mace Windu” gives him a book that was supposedly given to him in Palpatine’s will: it claims to contain ancient Sith secrets on cheating death. They’re all stuff Palpatine made up, but Anakin will think they work because Palpatine will simply decide not to kill Padme. He also claims that he found out about Anakin’s marriage, and thus Anakin is expelled from the Jedi Order - but because the war is over, Obi-Wan is gone, and Padme is seemingly saved, Anakin doesn’t mind at all and takes the opportunity to leave his old life behind.
The Skywalker family lives happily ever after… but at what cost?
I honestly spent way too long writing this.