Well Alice is the victor for this round which pleases me.
Anyways time for the next round:
Keine vs. Nitori
Keine
Pros: Teacher, historian, has were-hakutaku form as an added bonus. Nice color scheme for both forms. Fluffy tail for hakutaku form. Unique companion affair with Mokou
Cons: Very strict no non-sense type may turn off some, same can apply to head butting students, being CAVED (memetic fanon)
Nitori:
Pros: Cute mechanic, Shyness factor, lush color scheme fitting her aquatic theme, some degree of companionship for Marisa, cucumber appeal.
Cons: Kappa myths may turn some away, some feel she takes away from Marisa's magician crew (though that's debatable)
Advantage: Nitori
Course despite that, I will state my vote for who I choose.
Keine has always appealed to me as she's one of the few charters that I think of that belongs in the mature charter list. Her teacher complex is what make her both mature and a very appealing character in general. It's what I love in a charter is one who is there to help, protect and be a guide. She's sort of fits in the casual, but noteworthy tier in Touhou characters. Sure she can be rough with you as a teacher, but it's sometinhg I like about her. The aggressive, yet caring type. And probably one of the few charters with some interesting fanon material that usually focuses on her an Mokou in general always made her a worth while charter.
Nitori is cute, she's fun, and has a bunch of appealing things about her. She has a nice set of colors that fit her theme nicely and being a kappa with a knack for engineering is always a bonus. She always comes across to me as the cute shy mechanic which I find fun. And while her companionship with Marisa is interesting, I can't help but ask why does kappa become part of a magician harem, it's probably the only thing that I keep wondering about her. That and her youthfulness (which is why I tend to favor more mature charters most of the time unless there's something special about them)
Because of this, my vote is for Keine.
For the glory of the Teacher of the Human Village!