So they really can't be blamed then? The Devil made me do it!
Or consider a Faustian bargain.
Stalin got his, for sure. Absolute power over his countrymen for how many years?
Hitler, well, maybe der Fuhrer didn't read the fine print on the contract…
The possessed are usually so by their own consent.
Think "Faust." Reminding me,btw, of Roert Duval's film "Stalin." A character who was being purged threw the accusation into "Stalin"s" (Duval's( face. What was interesting was Duval's reaction. It was the face of a person "caught out."
No, that's a misunderstanding of demonic action. For one thing, a demon can persistently torment, tempt and attempt to persuade absolutely anybody, including the most virtuous (even Jesus Christ was tempted in this way)--- but cannot actually possess anybody without their consent.
The consent could be fleeting --- you could be drunk, or just fooling around --- which is one reason it's not a good idea to "fool around" with satanism.
Moreover, you can commit a crime while possessed and still be personally responsible and personally guilty. Only God can know for sure how much of the action was coerced and to what extent the person's action involved full knowledge and understanding, and full consent. Yet, even if Hitler and Stalin were literally hearing demonic voices telling them to carry out a program of murder, we still have to presume that they were personally responsible for their actions.
I don't think it excuses them. They invited him in. But they definitely were not of the Lord.