Obviously, I think about Star Wars a lot. I basically rebuilt a new timeline due to some meddling kids messing things up and changing how the past played out.
One thing I thought about was whether Palpatine knew the prophecy and guided Anakin to be trained by Obi-wan. He then sent Darth Maul to force the Jedi's hand in regards to the prophecy. Then, knowing the importance Palpatine manipulated the whole situation from behind the scenes until he was finally able to turn Anakin into Darth Vader.
Now Lucas himself has stated the balance is only Jedi, no Sith. This is because the Sith are like a cancer stealing from the force. The Jedi have a balance of give and take from the force.
Palpatine may have incorrectly believed that either the balance was equal Sith and Jedi or perhaps he thought he could change the prophecy by stealing the chosen one from the Jedi. In thinking this he took Vader as an apprentice, gave him everything to insure the destruction of the Jedi, but as we all know there was a failure to take into account Luke. So while the Sith took over and ruled for a while, the missing element came in and helped facilitate the Chosen One to destroy the Sith. Here's where Lucas says game over. Nothing happens after that. His eyes are Star Wars = Anakin's Journey.
So now what if we add in a powerful ancient Sith, capable of slowly manipulating Palpatine (perhaps only to a small degree). At the same time, someone that can act as a tool for Palpatine to maintain control of the Empire.
This all plays into the new world somehow. More on that later.