On the topic of TNO series, I believe a very compelling storyline can be made around Vladimir III. Like his background of being forced into collaborating with the Germans and how that baggage sticks at the beginning. His mental health as well as his handling of political tensions with the Kadets, Solidarists and Conservatives. Plotlines would be the defeat of the Aryan Brotherhood, thereby kickstarting his redemption in the eyes of the Russian people as well as symbolically breaking the spectre of his affiliation with the Nazis, his interactions with his former collaborationist cohorts in Samara, the manipulations of Burgundian agents as they try to co-opt Vladimir for their own ends and perhaps some inclusion of Tabby and the OVRI, and how Tsarism could lead down a very dark path.
Tukhachevsky's WRRF would be the ultimate villain of the West Russia Arc, that ends with Vladimir crushing the tyrannical Communists in the north, as his subjects start to take a very favourable view of the Tsar, in spite of his past, while they turn there back on the WRRF that they once held in high regard, as it's rulership degenerates into the brutalities of War Communism.
Assuming that the WRW2 is left as a series cliffhanger, I'm thinking that the Series end-villain would be Sablin, who begins as wanting to create a more humane USSR, then ends up as a downgraded authoritarian neo-Bukharinite. His journey would be explicitly analogous to that of Lenin, who initially preached Soviet Democracy and freedom from Tsarist autocracy yet ended up creating a worse tyranny than the Tsardom that he opposed. In the end, a liberal Russian Empire under Vladimir ultimately stands triumphant against the fallen hero Sablin. Vladimir earns his final piece of redemption as he liberates Siberia and gears up for his final test against Nazi Germany that has become ripe for pickings after Bormann's death and political crisis that ensues.