[@Shiyonichi]: Okay, I have multiple problems here, but let's try addressing them one at a time.
[list][*]The thing with 'force of nature' villains is that they are usually intended to "force progress" or create some sort of risk/reward factor. You mention, say, Lu Bu or Nemesis, but I'd also put villains like FE3H's Skull Knight or FE9/10's Black Knight in that. But, like, even putting specific generalizations aside, three of those four examples have a meaningful character behind them... And can be/ARE actively avoided.
No, seriously. Most engagements with Lu Bu in DW games can be dodged around, for example, and you're never meant to take him down but also never meant to directly engage him in normal combat (or at least not before the game gives you the okay to). Sure, all of those characters can pop up and force player movement around them, but only Mr. X/ Nemesis actively pursue the player (and, like, RE is a horror franchise; they're MEANT to be that ever-looming presence that creates tension when you have few tools to effectively deal with them). The others appear and may posture a bit, but because of their nature as scripted encounters, usually won't actually jumpscare you for no good reason. Usually. And then after the fact, you're able to effectively play around their presence because they might only jumpscare once or twice, if ever.
In short, I am of the opinion that even 'force of nature' villains should have proper character and motivations, regardless of what service those might actually provide... To say nothing of the fact that you just want the character to pop in for a random gank and murk a bunch of party members on a whim. That is, in my opinion, a bad design for a recurring character that would have no place in most scenarios; doubly so when the inherent presence of the character would warp gameplay to such an extent that you always have to play around them even if they never actually arrive... And in and of themselves have no inherent counterplay to deal with besides "just deal with it". Otherwise, villains who posture to just go around murdering people but have no meaning in the grand scheme of things are just handled as one-offs anyways OR end up becoming more of a nuisance to the player's progress rather than any sort of looming threat... Because, well, they wouldn't meant to be ones in the first place. This is completely divested from the personality of the character in question, but on that note...
[*]I still don't like the idea of the personality being what it is. The idea of a character basically going "and then I occasionally have sudden psychopathic urges and a desire to kill" feels super ham-fisted in my opinion, and if I'm going to be honest, I don't think I'd want a character in the RP who would do something like that. This is to say nothing of the power you've put them at to begin with, which would basically equate to "okay now we have a girl who probably needs actual psychiatric help wandering around who could at any time just murder a cast member" when you consider that a fair chunk of them don't actually have any sort of combat capabilities. That, I feel, is more problematic than the actual 'core' personality being proposed here. I don't really [i]care[/i] if the mental image of a big bad hulking monster who would snap your spine like a twig is all nice and friendly because it'd be 'funny' when the cast will try to actively avoid them anyways by dint of their nature AND because of all the metaknowledge they would have. It creates problems in terms of creating natural interaction between characters and just generally creates dynamics that aren't fun to play with or around for the most part.
[*]There are, again, better and more meaningful ways to lead to circumstances to get a character from that sort of background integrated into the world in which the characters exist in. I do once again want to emphasize the idea that, being presented as the world of an otome game as it is, that this school has very high ranking children of nobility and royalty present. Allowing a child picked up off the street to enroll for no reason beyond saving the child of the headmaster for and ignoring the prerequisites of knowledge needed to enter to begin with and not immediately fall behind/drop out is pure folly in my opinion, and would reasonably never happen in a sane world.[/list]
My opinion, fundamentally, does not change. I don't like the character as they are presented now, and the logic and justification behind them doesn't change that fact. These follow-up statements, coupled with the points I made in my last reply, still stand. Character still rejected for the reasons given prior.