Just for heck of it KOTOR 3 idea

So if you know anything about the events of KOTOR you know that despite of Revan and the Exile's efforts the great war takes place. But it never explains why they failed to stop the sith. The "sith emperor" formed a council of sith lords in the unknown regions. So here's my idea.

The sith emperor sent one of the sith council members to infiltrate the republic long before the beginning of the mandalorian wars as a senator. Over the course of time he is able to become chancellor and takes Kreia into his wing and seduces her ( i know it's gross but i figured they would both be old so whatever) right after she's exiled from the Jedi. He is the one that convinces her to trace revans footsteps therefore ultimately being behind the sith triumvirate. Revan discovered the identity of the chancellor shortly before departing the galaxy which set off the first Jedi purge courtesy of the chancellor. During all this time the Chancellor is slowly corrupting the senate to bow to his will.

Years later the exile finds revan in the unknown regions and Revan tells him he is faced with an ultimatum: stay and fight the sith waiting in the dark or return to the republic and cleanse it of it's plague. They decide that if they don't return then the republic will certainly fall. But if they kill the chancellor it still might be possible that the republic can win against them in the centuries to come. Revan then reveals that he was actually planning his return and took precautions for it years ago. He says he doesn't want the public to know of his return because he will be able to kill the chancellor best if he is stealthy. He then says that upon departing the republic he traveled to a newly discovered and mainly uninhabited planet of strange beings that were able to make clones(Kamino obviously) and had a clone made of Carth Onasi. Revan and the Exile travel there and pick up the clone. They return to Coruscant and the exile kidnaps the admiral. He and revan are united and Revan asks carth about Bastila. He tells him he hasn't heard from her in years and he presumes her dead. They transfer carths memories to the clone and the clone takes carths place so carth can assist revan and the exile and not be charged with treason. They use the long abandoned Jedi Temple as a base of operations where they devise a plan to shift the leadership of the republic to Carth. They plan to do this by completely wiping out the corrupt senate and the chancellor so that the admiral will take up the mantle of chancellor and will be given the emergency powers necessary to restore and re-stabilize the republic. However the problem still remains that there are three generals in between the chancellor and the admiral. So revan calls in a favor to Canderous (who has returned to Dxun) so that the three generals will be KIA by ambushes from "Mandalorian Raiders". After this is done Carth uses his level one clearance to plant lithium ion charges of a very powerful nature in certain areas in the senate room that will cause it to collapse in on itself. That night after this task is done the Chancellor makes a press conference stating that the newly manufactured Thermal Cluster Bomb will be used for the first time in the field to level planets on the outer rim that are not part of the republic in a bloodthirsty vie for power and the admiral is due to be the courier for this task on his flagship. The next day during a senate hearing Revan enters and force jumps to the senator's center podium and kills his body guards and makes the podium descend to the chancellors office. Then revan sets off the charges. After the senate is dead Revan and the chancellor have a whole speech about good and evil and *beep* and just as revan is about to slay him the chancellor puts revan into stasis. Then calls the admiral (carth's clone of course) over the com and tells him to load the bomb prepare his ship for immediate take off. The chancellor proceeds to stab revan with his lightsaber but finds his stasis field impregnable. And frustrated runs off to his ship while avoiding hundreds of reporters asking for his response to the senate killing and who the man was that leaped to his podium. Eventually Revan's stasis wears off and revan, the exile and the real Carth head to the hawk to pursue the flagship. When the ebon hawk transmits the proper code identifying it as a republic vessel carrying a high clearance official it is allowed to dock on the flagship. After subduing the guards there to greet them Carth Revan and the exile sneak their way to the bridge (note at this time the chancellor is overseeing the preparation of the bomb but still feels the revans presence within the ship) and carth himself shoots his clone directly in the forehead. and assumes his position on the bridge while the exile and revan go to confront the chancellor. When they find him an epic lightsaber duel occurs to where they discover that not even their combined power can out duel the chancellor. When the battle stops the chancellor reveals that he himself slew bastila in his own office. This enrages revan and he makes a foolish run at him resulting in his decapitation. At this time carth enters and his alliance with revan is revealed. Out of his rage and last ounce of might the exile uses all of his force power to put the chancellor in to stasis and orders that carth set the thermal bomb on a timer and evacuate the crew while he remains behind to keep the chancellor under stasis. Carth reluctantly does this and evacuates the crew and himself. The exile and the chancellor go down together. And neither the exile's nor revan's return to the republic is known to anyone except carth who proceeds to restore the republic and prepare it for the great war.