Joseph finds that he hates Chise for reasons that he originally can't comprehend, though its later revealed to be because his old personality was too similar to hers. However, he saw her body as a potential backup as her body would constantly heal any injuries she suffered. After she peered into his memories, he attempted to attack her, but in the aftermath of the battle he has decided to relent for a century because of her defeating him.
Joseph originally took pity or empathized with Cartaphilus, taking him into his home and taking care of him. However, his efforts eventually drove him to desperation and he merged with him, resulting in his current state.