This one was fun to do~
Watching xxxHolic and Jijoku Shoujo simultaneously causes you to notice a lot of differences between Enma Ai and Yuuko Ichihara.
First off, the physical similarities between these two are almost uncanny: black hair, red eyes, not to mention the almost identical haircuts...
There are other similarities, too. They both grant something (hence the title) - one grants wishes, the other, revenge. They both can be calm and wise, putting work above all else. They're both supernatural beings with supernatural buddies that move in and out of a supernatural world, while still dealing with our world. Only people with a special wish or desire can see or talk to them. ....eeyup, I think that's all of it...