They should make a horror game where your companion is possessed, and alternates between helping you and hurting you. You never know when they switch until suddenly they try to fuck you over. Like one moment they're trying to get you across the rope bridge, the next moment they're trying to cut it. Or you're both trying to get through an area and suddenly they are hunting you with a knife. You gotta survive until they switch back, and you find them clueless sitting alone somewhere, like they don't know what happened. But you can't ditch them because they're family or some shit.