Decades after the events of Skyrim, a great threat will force the Thalmor, the Empire and all the other major factions to unite.
The Hist once again recalls every Argonians back to Blackmarsh as it senses a great threat coming.
The Ka Po Tun Empire launches a massive invasion that spearheads through Blackmarsh with ease, not even the Hist empowered argonians would stop this. The Ka Po Tun would than divide its forces and successfully conquer Cryodill and Elsweyr. The Ka Po Tun troops would look like humanoid dragons with orange with black stripes. They're leader Tosh Raka would be a full dragon instead of the standard humanoid dragons. It doesn't end here, the mighty Ka Po Tun are constantly sending in reinforcements still. The standard Ka Po Tun would look like this http://wowpedia.org/File:Maxnar.jpg except orange with black stripes of course.
Meanwhile the Kamal snow demon invades Morrowind and without the Tribunal gods and the full might of all the great houses, Morrowind falls easily. Skyrim gets invaded next but even with the might of the new High King's forces and the Dragons, the rampaging snow demons led by a new demon king proved to be too powerful. The Dragonborn is nowhere to be found, some say he went away, some say he went into a certain daedra realm, and some even say he/she was killed in the invasion.
The Ka Po Tun began sending massive assaults towards the rest of the Provinces that aren't conquered yet. So far they are holding back the attackers but for how long? In summerset isles, the Psijic Order has been working on a new project, a new god similar to Akulakhan and Numidium, once completed it will be powered by the Eye of Magnus which seems to be the only hope of pushing back this invasion.
The Four Great Powers of Akavir
Kamal Demon King - The new Demon King is even stronger than the past one. The past demon king that invaded was only defeated in a epic battle by Almalexia and the Underking.
Tosh Raka the God Emperor - The largest dragon in the world and also the most powerful. Instead of charging into the battlefield like most dragons, Tosh stays in the back and commands his massive army as he is also a master strategist.
The Monkey king - The mysterious and elusive leader of the Tang Mo carries many ancient artifacts on his body. But these aren't just for show as each artifact allows him to do near impossible things from destroying a entire town to sending someone into a alternate realm.
The Lost Hydra - the unknown leader of the Tsaesci long killed by Tosh Raka, The Tsaesci still worships it as its spirit form still whispers and guides them. Some say the hidden Tsaesci agents are among Tamriel already, disgusing themselves as the races of Tamriel