While a bit exaggerated just for the fun of it, Yuyuko could be the person I fear.

 I mean, firstly, she's a ghost and I'm NOT a fan of them. They give me the feeling of dread, and it also can make me feel paranoid, fearing that the worst will come at me. Secondly, she have the ability to kill someone without even moving a finger. Yup, but thankfully, she isn't THAT insane and have some morals in her. Lastly, this face.

That settles it. That face alone can make a sane man go insane, losing the grasp of reality. This is why, Yuyuko is the 2nd scariest Touhou character in my opinion. Seiga Kaku is the 1st all the way up, there is no way someone can be that deranged as her.

Anyways, thank you for reading, and God bless.