[Loumistro]

I don't really know where you are but I will tell you what I know about Rathpian and his location. There is some broken stairs and you will fall down them go ahead that is the right direction you don't really need Rathpian so I killed him. but you continue on your way down you give him the rat pie and there will be a chest in one of those rooms over there go in it open the chest keep the crystal and back where you fell down there were some angels there will be a slot for the crystal there put it in and it is an elevator go up and kill that dude. turn around and push the button but don't go down the elevator get on top of it. Well that is all I will tell you. hope you get what you need out of that.