What do you think My Little Pony (in any of the cartoons, or even an original cartoon) would be like if it were the exact opposite of Friendship is Magic: A cynical action show meant for adult men? Would it even work?

Depends, does it play itself straight or is it aware of the fact that it's a show, targeted at adult men, starring cartoon horses in dead-serious situations? If it was played for laughs it might have a small following and I could see it as being like any of those weird shows on Adult Swim.

If it tried to play itself completely straight, it would have been cancelled in a New York minute. It's just too weird and out there.

It would be the history channel? 24/7 coverage of WWII.

It would be 90s Youngblood comics or other comics from the era. According to them, the power of friendship would be whiny ineffectual idealism that has no place in reality. Only strength, ruthlessness, and violence has get anything done. That and lots of guns and pouches.

7450161 The first thing that comes to mind is Rick and Morty, but Summer is the main character.

Or...we could end up with My Troubled Pony from Billy and Mandy......

I mean, first thought is something along the lines of Madoka Magica but that may be more an example of how far you can push the darkness without actually upsetting the core ideals by the end. Would the phrase "cynical idealism" work?

Charlie the Unicorn with action scenes.

No action scenes included.