Yes, it is extremely controversial. Hitler was responsible for the Holocaust and countless atrocities during World War II, and Stalin also had his share of controversial actions, including purges. Combining them in a fanfic, even in a fictional context, can be seen as disrespectful to the victims of their real - life actions.
No, it's not really appropriate. Stalin and Hitler represent two of the most heinous and immoral leaders in history, responsible for countless atrocities. Combining them in fan fiction in any sort of positive or romanticized way is disrespectful to the victims of their actions.
A third theme could be a political drama - like situation. The fanfic could be set in a fictional political arena where Hitler and Stalin are rivals in a different kind of power struggle, not the World War II - related one. It could explore how their ideologies clash or converge in a new and different political landscape.
One common theme could be the exploration of an alternate historical scenario. For example, how their meeting might have changed the course of history in a completely different way. Maybe it shows them negotiating some sort of peace deal that would have a huge impact on the world at that time.
It can be considered ethical as long as it is done in a way that doesn't promote or glorify their heinous acts. If the fanfic is used as a means to explore historical events from a different perspective, such as analyzing their political decisions or how different historical paths could have been taken, it can be a legitimate form of creative writing.
One possible theme could be a fictional exploration of their political ideologies clashing in an alternate historical scenario. For example, they might debate about different forms of governance and economic systems. Another theme could be a story about how they might have interacted during diplomatic negotiations, perhaps in a world where they were forced to cooperate for some reason.
It is highly inappropriate. Stalin and Hitler were on opposite sides of one of the most brutal and significant conflicts in history, World War II. Stalin led the Soviet Union against Hitler's Nazi Germany, which was responsible for countless atrocities including the Holocaust. Writing a fanfic that pairs them in any way romanticizes or distorts the historical reality and the extreme ideological differences and enmity between them.
The potential consequence is that it blurs the lines between good and evil in history. Stalin, despite his own flaws, was on the side of fighting Hitler's aggression. A fanfic like this can mislead younger generations who may not be fully aware of the historical context. They might not understand the true horror of Hitler's regime and the importance of the Soviet Union's resistance if such a fictional and inappropriate relationship is presented.
You can show his different sides. For example, his political shrewdness in public and his more private, perhaps even vulnerable moments when he's alone with the reader. Maybe he has doubts about some of his policies but can't show it to the public.
Definitely not. Hitler is associated with the most heinous acts in history. Jesus is venerated in Christianity. Creating a fanfic with such a pairing violates basic moral and ethical norms. It would be deeply offensive to many people, especially those with religious beliefs related to Jesus and those who understand the horror of Hitler's actions.