After seeing how hilarious the English translations were in the Dark Souls quick look, my mind jumped to the name of Dark Souls' spiritual predecessor, Demon's Souls. Then I got thinking... is the name wrong?
1. Demon Souls would imply that there are souls which are demonic.
2. Demons Souls is incorrect grammar, and would read as though you were stating two separate things: Demons and Souls.
3. Demon's Souls is correct grammar, but it doesn't fit with what the game is actually about. It would mean there is one demon with many souls.
4. Demons' Souls is what I believe the intended name was. It essentially means "the souls of multiple demons."
Demon's Souls, as is, could technically fit into the Demon's Souls universe, but it's a stretch, and I'd assume most people think of the fourth meaning I listed when they think of the game.
Anyone out there who knows Japanese maybe wanna enlighten us on what the real intended name is supposed to be?