I really hope she gets super jealous. The type of jealous that snake girl would jump for joy at seeing. Then to prove snake girl wrong she works through it and ends up even closer with otobe after it.
For real tho, everyone has potential for darkness. You should familiarize yourself with your inner monster and tame it lest malicious actors will take advantage of you. Being harmless is not a virtue after all.
Though the vital difference is, being in touch with your inner darkness is not the same as snake girls stupid philosophy of everyone being selfish and or evil but just having a facade.
Keisuke, otobe and kusunoki all are genuinely kind people who in the face of harship decide to still be good. Snake bitch just broke and gave up.
I posited awhile back that Hebikawa would have an arc that would see her addressing her own issues, and that Keisuke would be instrumental in helping her through it as someone who has/can "see through her bullshit" and call her out on it, and otherwise be unaffected by it.
I really hope that does happen, and she doesn't become a 2-dimensional character in her own right that serves as a prop for Kusunoki to Main Character her way into the romance slot at the end. Because it would also help her actually fall for Keisuke
for real, and would help him fully overcome his issues he developed at her hand in middle school - but in a healthier way, that isn't him just being mad at her and writing her off. They've had actual moments of real connection already, so I'm hoping that's going to be built upon further down the line.
I'm all but certain Kusunoki will win this because she's the darling FMC and the Botan Gambit is just a pipe dream at this point. But Hebikawa, and Otobe, gaining actual ground with Keisuke would at least hopefully spur Kusunoki to not be the flat, boring character she's become up to this point.
And Hebikawa especially would help in that regard, as she wants to see Kusunoki's darkness - and successfully wooing Keisuke away from Kusunoki, assuming the later actually
does decide to really face herself and stop being obstinante and wishy washy about whether she can deal with romance, would be just the method that has the most chance of successfully bringing that out of Kusunoki.
I'm bummed that both Snek & Tomboy are losing this one because of the very formula of this Genre Trope, but I'm at least expecting their characters have the same depth they've started with and don't just become props for the Perfect Heroine's Magical Actualization.