Hello there; your resident Rei fanboy here. Greed isn't the pinnacle of philosophical depth, but Greed is chatty enough that he'd probably pick at Rei's confusions with impossibly simple answers. Or get protective of her since she seems kind of fragile. Or just try to get reactions out of her. I'm not sure what directions you're looking to take her in or if you're running loose, but if you're desperate enough for CR for her to put up with me, I'd be happy to try to set up something.