Putin is a toxic narcissist, a war criminal, the kind of person who could open up his own wing of Hell.
That said, while he may have started this war, I'm not sure how much control he has over it anymore. Or that whoever might come after Putin will be any better. The whole Russian political system is rotten and toxic to its core. Axing the figurehead might not even change that much.
The West should stay out of that viper's pit, doing something like that would only confirm the worst assumptions underlying Russia's hysterical warmed-over Cold War-era propaganda.
Anyway - Russians will decide the fate of the czar, one way or another, like they always have