Here's my understanding:
Some people believe during the tribulation. They make into the 1000 year reign.
During this reign, there is peace on earth.
At the end of the 1000 years, Satan is released. Some of the descendants of the believers follow Satan.
There is a final battle.
There is final judgment.
New Jerusalem arrives.
Now, what is the point of the 1000 year reign here? Is it to prove that Christ can do something that Satan could never do (i.e. real world peace?)