First, you need to convince Cirno that she's weak in the first place. That's not likely to happen, especially since as faeries go, she's actually VERY competent. The problem is just that youkai, humans, oni, and divinities are all generally stronger than faeries as a whole.
Another linking factor is how nocturnal these three youkai are. A nightsparrow that causes blindness and confuses hearing with sound, a darkness youkai who sunburns badly and has the power to extinguish all light around her, and a youkai firefly.
By contrast, it hardly matters to Cirno whether it's day or night.
Skyknight said: First, you need to convince Cirno that she's weak in the first place. That's not likely to happen, especially since as faeries go, she's actually VERY competent. The problem is just that youkai, humans, oni, and divinities are all generally stronger than faeries as a whole.
Though in GFW Marisa all but said that Cirno has reached a level of power where even she, despite ranking third on the power ladder (under Yukari and Reimu), might've lost to Cirno even if she'd popped her youkai wings from Seihou and gone full-tilt EX Boss on the little scamp. Cirno is getting stronger. Stronger than any fairy ought to be.
I think Eiki even said she might be halfway to becoming a youkai.
Though in GFW Marisa all but said that Cirno has reached a level of power where even she, despite ranking third on the power ladder (under Yukari and Reimu), might've lost to Cirno even if she'd popped her youkai wings from Seihou and gone full-tilt EX Boss on the little scamp. Cirno is getting stronger. Stronger than any fairy ought to be.
I think Eiki even said she might be halfway to becoming a youkai.
Marisa is nowhere near to that level, and the same goes for Reimu. Marisa herself says that the SC rules are there because there are "too many strong youkai", and basically every final/ex boss (and some others like Yuugi the motherfucking oni deva, Aya, Suiki, or any of the lunarians) is stronger than Marisa and Reimu. They win only because of the rules, and even so only because they try an undefined amount of times. Seihou and Marisa going youkai have nothing to do with this, since it's not Touhou canon.
And Cirno lost despite: -Marisa being drunk (SoPM) -Marisa going easy -The match never going near to Cirno's victory (SoPM) -Cirno CHEATING all the fucking time. Because let's face it, freezing bullets every time because she's too shit to fight normally is cheating. You could say she was literally bombing all the time, and everyone could do it, those three above included, although with different means.
So yeah, she's strong for a fairy (and as of LoLK, explicitly weaker than Clownpiece), but not as strong as most people usually think. Besides, Mystia defeated higher-class opponents in PoFV just like Cirno, but "casually" no one remembers this, and both Rumia and Wriggle are roughly at their same level.
