About the Flan stuff - This is about all I know to say about it:
http://en.touhouwiki.net/wiki/Article_and_Interview:_Flandre"She usually can't leave the house because of her emotional instability."
Should be pretty self-explanatory? She can't control her power (which, she's ridiculously powerful even by Touhou standards), and she's emotionally unstable. You wouldn't let someone like like that go around doing whatever they want either.
At the very least, I think this should properly prove that she does in fact have some sort of a mental disorder. No, that is not the same thing as saying someone is retarded. Flan is not retarded. Well, technically vampires never grow up, but that's beside the point.
I can't explain exactly why I hate it without sounding like a feminist, and I hate feminists... I'll just try to be quick and say Touhou is the only thing I know that really has an excess of strong female figures who aren't strong or "badass" only because "badass women are sexy". I mean the fanart might depict them as sexy or hot or something. But at its core, they are who they are. They weren' t made that way just for male sex appeal. It's nice being able to admire women for a change without having that sex-related alternative as a secondary motive.
I completely agree with you.
Well, I don't have a problem with mannousuke though, besides that people are raping a decent character when they do it, and that it is rather ridiculous.
I don't know if this counts, as I've yet to play LLS or PoFV, but is Yuka really as crazy about her flowers as some people have made it seem? Even though she's a flower youkai, I don't think her personality is like that. It just seems too extreme for any character.
Yuka is canonically a person who plays with people for fun. No, more than that. Everything is a game to her. She said that to Eiki's face in PoFV. And her actions back it up. She tore up Makai as a game. She learned the ultimate magic as a game. The Yama told her she's lived a bit too long, and she enjoys playing with people too much, but the ensuing battle was only treated as game by Yuka.
The theme that plays when you wake her up in LLS is not called "Sleeping Terror" without reason. She may be lazy, but those who wander into her flower field or her mansion and poke around a bit too much will end up dead.
In Perfect Memento, her Threat Level is "Very High" and her Human Friendship Level is "Very Poor." Regardless of how polite she may act around others, this should give you some idea that something is wrong here. Not to mention, the same article says that she "seems peaceful at first glance but is merciless towards other creatures."
Yeah, I do believe she's sadistic. Is she really the ultimate sadistic creature? No. But she is extremely dangerous and her morals are very lacking. If you piss her off, she will rip you to pieces. And even if you don't, if you're in her way she'll still intentionally rub you the wrong way (read: troll you) and then beat you up.
The only reasons she doesn't "play" with everyone are:
1. She's lazy and likes to sleep a lot, tending to stay in her flower fields or in her mansion for long periods of time.
2. She's not interested in boring battles. If you're weak, she won't bother with you unless you piss her off.
[EDIT: Ah right, there was one last thing I wanted to say. I actually did come to like EX-Keine a bit because of this:
http://danbooru.donmai.us/pool/show/1074And other comics made by Pageratta. He is hilarious.]
