Here is a fandom fact you might like.
- Yukari's power over gaps tend to lead to many moments where she does something to screw over not only Reimu's life but other denizens. It's usually referred to as "GODDAMNIT YUKARI!"
Example: Reimu and Marisa are enjoying their time talking. the last Manju was taken by Yukari without them noticing. Reimu blames Marisa and through misunderstandings, beats Marisa up in a fit of rage. Leaving Yukari the laugh at the events. Schadenfreude at it's finest.
- Utshio is a bird, so many times in works with the underground crew, she sometimes forgets what people say or just sets her mind back on a boiled egg to consume. It's never really proven if Utshio is indeed forgetful or stupid. Much like Cirno.
- Speaking of Cirno, when people make the Baka joke of Cirno, it's referring to her placement in the Instruction manual in PFV. Mainly how the Number nine characters on the manual read out as "Idiot" and so, the ⑨ became the official number of Cirno, leading to many jokes of her...
Look at the image and see the 9 characters. That reads to Idiot.- and in fact, when Cirno means she is the strongest...she is talking about among all the fairies, not scaling herself against everyone (Though she does fight the humans here and there). In Fairy Wars, Cirno does indeed fight Marisa (as EX boss) but she wins because Marisa went easy with non-lethal lazers. And with the fan theory that the main characters get stronger since Touhou 5, it can be implied that if Marisa does not use her Master Spark, Cirno could indeed beat her if she managed to really go all out.
(Which could put her around a stage 4 boss in terms of power if we go by games and the theory)
- Finally: Yukari, Eirin, and Kanako are paired usually in fan works due to their family names containing a character that can be misread as "Old Hag"