In fact, years in the future, but not many, Cloudsdale decides to secede from Equestria entirely. Realising that this will result in no weather changes and the eventual desertification of Equestria, Celestia gives one ultimatum - Surrender, or have Cloudsdale destroyed and all Pegasi forced into slavery.
Cloudsdale takes a third option and wires the Rainbow factory to self destruct in the event of Cloudsdale's defeat, showering the whole planet with Rainbow Radiation, before armouring their military in Rainrad Resistance Armour. The Cloudsdale Militia launches an attack on Canterlot, while the main force attacks Manehattan. Celestia and Luna attempt to use the Elements, but due to the armour on the pegasi units, it fails.
Celestia creates a new weapon, the
Anti-Army Mechanical Armour Frame.
The Mane Six are selected as pilots, although Fluttershy deserts and takes her frame to griffon territory, where she spends the rest of her life as a mercenary, and Rainbow Dash defects and joins the Cloudsdale forces because she decides she simply cannot beat her own species into submission, and the rest start to constantly question their orders, and even outright defy them at points.
And that is Season Four.
edited 6th Nov '12 9:34:24 PM by Steventheman
The metal of your chains is no match for the metal in my veins.