This game right here! It will be perfect for pewdiepie. it got all the scary kinda things, and it is a game i think that even pewds can make fun of. Even though it is a first persoon shooter i think that it fits perfectly.
You can kill in the most evil ways, and sometimes you even have to solve som puzzles. You are with you squad but sometimes you get separated, and that is where it is really fun. i will not spoil the main plot, but it freaked me out pretty hard.

youtube.com/watch?v=sSFBCrHubSE