The timeline is after the Buu Saga, in a rather different dimension. The lives of the Canon characters in very different, as if the past events had never happened.
The Saiyans have returned to power, they have their King has been revived, King Vegeta, he once again holds the throne. Frieza has been searching the universe for Changelings that have been run out 200 years ago. He has also rebuilt his army. King Vegeta and Frieza are at war, the war is spread across distant planets in the universe, causing chaos to innocent people.
Dr Myuu and Dr Gero have been testing their new Androids on Humans on Planet Earth, before releasing them from their sleep to do whatever. Dr Myuu has planned to overthrow Planet Earth with his Tuffle Androids, killing Dr Gero in the process.
Babidi has decided to awaken Majin Buu when the war is at it's peak, searching the goal of taking over the war, in his attempt to destroy the universe.