I need some help on how to portray the gradual descent of my MC (in my story) into insanity. My MC isn't exactly a good guy, many events in the past have traumatized him, and he has some traits of a pshycopath. My MC has the curse/ability to experience other people's lives as they have happened/ are happening/ will happen. Thing is, he can't tell which one it is, and this eventually drives him over the edge. I want to know how I could portray his descent and make it seem feasible.