
Because canonically, espers feel a sense of possession over their guide and the higher the compatibility, the more that effect is amplified. While this is general, for this specific manhwa, I don’t know the whole background but it should follow the same pattern. Not to mention, the higher the rank of the esper, the more prone they are to being crazy and psychotic because they have a hard time finding guides that fit them so the after effect of their powers is stronger and more common to them. In short, they’re more unstable. In reality, why are the seme yanderes? Cause the author loves it, and we love it.
So I haven't read a lot of guideverse but if anyone is into it why are espers always eventually going yandere is that like a genre staple? lol