Prologue
Anakin and Ahsoka went to see Chancellor and saw that three Jedi were dead already. Yoda, Obi Wan and the rest of the Council who were alive were fighting Darth Sidious but were killed one by one. Soon, Palpatine stabbed Yoda and the little green troll fell on the ground. After that Sidious saw Anakin and Ahsoka.
-A, hello young ones. Those Jedi were traitors and they were about to kill me.
-We don't believe in those lies Palpatine, or should we call you Darth Sidious?-the two asked
-So be it. If you two do not want to join the Dark Side, the you will die!
Palpatine sent lightning from his fingers but the Jedi deflected them. Palpatine then pushed both of them away. Anakin Skywalker jumped and cut one of his hands, unfortunately it was the wrong hand.
-You will lose Jedi, this is inevitable.
Ahsoka jumped and fought with the sith while Anakin was lying on the floor. That happened because Palpatine sent a huge portion of lightning at him right after Anakin sliced off his hand. Ahsoka was fighting and fighting, but the little girl was no match for the sith lord. The two fough over and over again and Sidious soon destroyed Ahsoka's lightsaber.
-Now, you die!
He pointed the lightsaber into her throat but Anakin was faster and jumped before her. Instead of Ahsoka, Anakin got stabbed in the stomach. He was very weak now.
-that was a waste-said Sidious
He was about to kill Ahsoka as Anakin took all his strength, force pushed his lightsaber and with all his anger sliced the sith's head off. After that he dropped on the ground. Ahsoka came closer to Anakin and hugged her Master.
-Don't die Master, I need you.
-Sorry Snips, but it's my time. I fulfilled my destiny by destroying the sith. Now I am done. Soon, I will become one with the Force. Ahsoka-he asked her-promise me one thing
-Yes, Master, anything-she said as she cried.
-Please look for Padme and my future children. One day they will need to be trained in Jedi arts.
-I will Master.
-And as last living member of the Jedi Council I appoint you to be the next Jedi Grandmaster and Head of Jedi High Council.
-That is impossible. The Jedi will not follow me. And I am too young to even be a Jedi Knight.
-Your status as an apprentice of Chosen One will make people follow you. And I grant you the rank of Master, even skipping Jedi Knight status. Jedi need a new and young leader. I know you will be a great one. Master Yoda taught me how I will be able to communicate with you after I become one with the Force.
Soon after that the Chosen One, Anakin Skywalker has died. Ahsoka called clones, as well as some Jedi to help her to bring the bodies to the temple. In the evening Twelve Jedi were burned in a ritual Jedi ceremony. Ahsoka saw Padme crying.
-Senator Amidala, don't worry, life will improve.
-Anakin died.
-I loved him too, he was like a brother to me but he is dead. He fulfilled his destiny and now he will rest in peace. You are welcome to share my quarters.
-Thank you for all your kindness Ahsoka.
Next day, Senators elected Bail Organa as their new Chancellor. Padme moved to live with Ahsoka and Clone troopers finally captured the Separatists Council. They were on unconditional terms and signed the treaty. The war was over. Ahsoka now was the Jedi Grandmaster and she elected new members to the Council. The new Jedi Era has began.
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To clarify a couple of points. Obi Wan defeated Grevious and safely returned to Coruscant. Anakin did not believe Chancellor about his ideas. And for the arrest, eleven members of the Council went to fight with Dooku, leaving Anakin alone because even then Mace was suspicious because he did not really trust Anakin. He does now in Jedi afterlife.