Even after all these years, the true demon path in "Soul Nomad and the World Eaters" still punched me in the gut the hardest.
I should probably quantify: with games like Spec Ops and the like, I knew ahead of time that the player punch was coming, which helped to soften the blow. World Eaters, though, was a Nippon-ichi software title. Yeah, they called the route "true demon", which would normally have been a clue that some horrible stuff was about to go down, but the previous 'dark' storyarcs NIS had done were things like "demon queen etna" in disgaea, and other such tongue-in-cheek stuff.
The true demon path of World Eaters had its fair share of dark comedy, sure, but unlike literally EVERY other title NIS has ever made and ever will make, that dark humor was utterly buried under wave after wave of terrible events, with the characters you knew and loved in the proper game having their hope slowly drained, and the only characters who remain by your side being broken shells of people who just want to see the world burn.
still one of the best games by the publisher though. highly recommended, though the demon path is only for those with a strong stomach.