The main idea of Heroes 6 is the conflict between Darkness and Light. In the original Heroes games, the campaign covered the pre- and post-eclipse eras, i.e., a time of still-hidden conflict between darkness and light. This is like a prologue to the story that the developers are afraid to tell (this is how they describe it in their latest interview). What is the very last video after completing the epilogue in Heroes 6? Yes, yes. The Faceless Ones want to attack the world, but they have a treaty. For this purpose, Railag is summoned, and the post-eclipse era begins, i.e., the time of the plot for as many as 2 add-ons (the add-ons we are talking about. They have not been officially announced yet). The plot of the first add-on: Railag gathers an army independent of the Sylvan Elves (the Elves of Erathia) who are susceptible to darkness, but these are still the same Forest Elves (a new faction), and he goes to war. Also, the Academy (a new faction) enters the arena. At the end, the contract is broken (with the possible active participation of the Academy), and the Faceless Ones can attack Ashan. The plot of the second add-on: Railag is defeated, but the contract is broken, and the weakened Dark Elves are strengthened by the Faceless Ones. They are driven into the Dungeon. But Railag does not give up. Transforming the Elves into Dark Elves (a new faction), he goes to a new war. BUT! this is the Dungeon, and here are new enemies - the neighboring Dwarves (a new faction). They are fighting for a place under the Sun... Earth. And then, to the sound of music :) Kirill comes to the forefront. For the second time, he defeats Railag, and completely breaking up the Dark Elves into groups, he transforms Railag into a Demon and seals him in Shi'o (why this is necessary - ask Kha-Belekh). Railag is defeated. The end. The last patches, and we are waiting for the release of Heroes 7.
This is my vision for the plot of the Heroes 6 add-ons. Perhaps the developers didn't even think of this, but in my opinion, this is the ideal plot.