Black Souls II!
Eroge aside, it's surprisingly difficult... I know it wears its Dark Souls inspiration on its sleeve (to the point some item names are identical, at least for the english patch), but I didn't expect an RPGMaker gemu to get anywhere near that kind of RAEG inducing level of gameplay that I know DS for. Kudos 2 teh dev for pulling that off. There's also a lot of choice of interactions too. Maybe I'll decide to do a raep everything route after I'm done playing through the game normally. (´￢`)