/slamming my hands up and down Yukari!! Yukari!!!
This might be an obvious one, but: Yukari has dreams about being Maribel. No, she is not literally Maribel, but she sees Maribel’s life in her dreams. The converse is rarely, if ever, true.
While her powers seem limitless, they really aren’t. They are limited to Yukari’s imagination. Of course, her imagination is large, which leads to her manipulation of boundaries seeming limitless.
Yukari helped Ran pick out Chen, and in fact suggested that Ran have a shikigami in the first place.
Yukari regularly takes things from the Outside World, but doesn’t often go there. She has, but it isn’t a regular thing.
She is a serious flirt. No matter if she’s actually attracted to someone, she will flirt with them, in an attempt to fluster them. This contributes to her less-than-positive relationship with Reimu – Reimu is very annoyed by it.
She is quite fond of humans as toys. Normal, powerless humans are very fun to mess with to her, but she would never befriend one. The reason she is friends with the human protagonists is because they have shown her their powers.