Depends on how you look at it. I bet there are quite a few girls in that classroom who'd say the exact opposite.
But the day isn't over just yet, so you might be right. Yuri is trembling so maybe she's about to collapse.
if she falls right into Ruri's lap then that will be a really bad day
The problem is, we don't know what kind of bane she is and why. Looking at her inner thoughts:
- Ruri seems to be a delinquent prankster who likes to stir up trouble. But she's not harassing boys openly to a point where the school notices and would react. Otherwise, as already mentioned, it's guaranteed that she'd get expelled for such behavior because the academy would never tolerate that.
- Given her Succubus like design... maybe she is playful with males but only if she's the dominant one. For cowards like the guy in her class that works well. For jerks like Yamada? She might use force to drive them out but the question is how and where she actually does it. Inside of the school someone would have reported her and the guards usually don't leave their guys all alone.
- Based on her own comments Ruri has some issues with other guards, especially Aya, Hana and Kaede, but it's probably not limited to them. If she is responsible for Class C and E male students dropping out, then she targets other classes and that might be out of rivalry for some and dislike for others.
- Her reaction to Yuri is interesting, to say the least. In the end, she hates her just as much as Sou. Her thoughts about that strong "Female in Heat" scent is that she actually finds it disgusting to the point she'd puke - a complete 180 compared to what it first looked like in chap 238.
- Her initial state was probably thanks to Sou's pheromones and she reacted to those first. After that Yuri's strong smell overwhelmed her - and maybe exactly that is what actually drove her off and cleared her mind. In a way, she should be thankful to Yuri right now. Ruri would have made a real mess otherwise.
- Furthermore, if Ruri physically dislikes the scent of an aroused female, then she's probably not into girls herself either. Bluntly put, a lesbian would get aroused by girls instead of guys but the scent will be essentially the same. So if she's disgusted by that then it's not gonna work for Ruri.
- Thus, I assume Ruri hates the general idea of losing oneself to lust. That holds true for others, but especially for herself. Mentally she doesn't approve the idea liking guys, physically she cannot resist. That drives her mad and if you look closely, she even has tears in her eyes. Being affected herself is what she hates the most and she redirects that anger back to the source of it all.
- In that regard, I would think that Ruri usually has her own lust strongly suppressed and under control. She must be good at it, otherwise she wouldn't be the grade's number 4. And it works really well for "normal" boys, because they are either annoying jerks or physically unappealing to her. It has been the same for Aya who was calm and composed until she met her dream guy... Ruri doesn't know Sou's personality but by looks alone she can tell he's dangerous.
Long story short - she will struggle desperately but she's bound to fail no matter how much she fights back.
And the other guys? Look at Suzuki, he finds Sou disturbing. The other males will likely be the same. If Sou's actions drive all the girls crazy, then the other men at school wouldn't get away unscathed. I mean even a harem master will have trouble to reign in close to 200 girls (five whole classes) and that's not even counting the other grades and the school staff