u/Dorkshire

Bear wishes for Nikki to love him, but what loves him isn’t Nikki. Whether she’s possessed or just deeply changed it’s not Nicky.

Which raises the question, does the one wish willow do what it says it does? You could argue that it does its best within the constraints of whatever its mechanism is, but I prefer the idea it was never intended to. Especially given the phone conversation with customer services and Nikki’s screams, it could be something much more malevolent than a simple wish granting device.