Season 8 should have been the Civil war against the corrupt president of the federation, after they attack DS9 they proclaim DS9 independant and get help from Mars, once on Mars, section 31 captures Sisko and brings him to Earth and tortures him. He's eventually saved and they manage to save Earth and the federation. Later on they let some Telepaths live on the station and Sher..Sisko gets to regret it because they start to cause trouble ending with a dramatic hostage situation.
After the telepaths are dead the Breen comes back to Cardassia and forces the Cardassian leader to do what the Breen say in secret othervise they will bomb and destroy Cardassia with hidden nuclear bombs. The Breen forces the Cardassians to attack others in secret eventually the romulans and klingons bomb Cardassia again and Cardassia surrenders but isolates themselves for the next 20 years.
After all that Sisko dies and goes to the first ones
After the telepaths are dead the Breen comes back to Cardassia and forces the Cardassian leader to do what the Breen say in secret othervise they will bomb and destroy Cardassia with hidden nuclear bombs. The Breen forces the Cardassians to attack others in secret eventually the romulans and klingons bomb Cardassia again and Cardassia surrenders but isolates themselves for the next 20 years.
After all that Sisko dies and goes to the first ones