Is it harder than Dark Souls? I think it could be. Darkest Dungeon has permadeath >.<
Personally as someone looking at these two games there is no comparison on difficulty, but which is the superior challenger for their genre? I think they're both at the top list for difficulty but very high rewards for the geniuses who can beat these very hard games with relative ease.
I guess a better question would be which is harder to learn and what's the easiest way to survive and level up. The most important aspects of both games are surviving, collecting gold or souls for upgrading and leveling up. But permadeath is the biggest bitch with DD.. thoughts?