Vikings and the Russian Revolution are EXTREEMLY interesting and neither have been done before to Ubisoft’s level unlike some of the other ideas which are kind of similar to what Ubisoft has done before.
We need to go further back to the Persian Empire so we can finally get some backstory on that hidden blade that killed Xerxes, and then realize there is actually more backstory to that weapon because it killed someone else of significance before that as well and we'll never truly discover the origins of the weapon.
They put Feudal Japan as an option so they have to be doing that. I'll be down to play as a ninja.
I mean, I know other games have done it before but Assassin's Creed is all about assassins and stealth kills and basically being a ninja, just get Japan done so you can say "k, we've done it" and then you can go back to periods that other franchises don't explore.
The Peloponnesian War between Athens and Sparta in Ancient Greece would be pretty epic but i think it's unlikely to ever see it in an Assassins Creed game. Other great choices could be, Feudal Japan, Joan of Arc battles, Conquests of Alexander The Great and Historical King Arthur.
such a great series that let us live these periods of history. any of them would be great, personally I have learned so much from Assassin's Creed and I want more. Russian revolution is very interesting though.