Thankfully you can't win against Cthulhu.
The universe and this dimension isn't meant to win against Cthulhu. He might just be a low level priest and not even a deep great old one but the only thing you can do is despair, go mad and if both happens too quickly rip your eyeballs out and eat them.
Darth Sidious is like Mother Theresa and Ghandi combined when you compare him to Cthulhu.

It would have been quite glorious for Stalin because he would be something like a Messiah of peace and love in comparison.
To be forced to go to a Siberian Gulak and submit to the freezing cold and forced labour would be a 5 Star holiday relaxation if the other side would be a single of Cthulhu's nightmare.

It's like Stalin is the Common Cold while Cthulhu is the sum of the Plague, Ebola, Marburg and Rabies combined and from outer space.

What is Cthulhu?

ROTFL

*points at tinyE's avatar*

Thanks, you just made my morning. :D

(I'm assuming that was facetious... if not, just Google it and you'll understand why, given your avatar, that's very funny.)

What is love?

Baby don't hurt me

Shrek is love.

... don't hurt me, no more.

Love is Shrek? No wonder I haven't found it (too grossed to say him).

Not sure who would win, but I'd prefer Cthulhu

You cannot gun down Cthulhu, so Stalin does no have a chance.

Nevertheless, I would be the winner, because I would take over the mental institution's business. And as we know, evertime Cthulhu is involved, people go nuts.