I don‘t have the same knee-jerk reaction to “love rivals” as other people. Sometimes, they are just false flags, not really rivals at all. Other times, main couple’s relationship is so tight, there isn’t any space between them for a rival to fit, making them a non-threat at worst, and an unwitting ally at best. Seeing how hopelessly into eachother Fumi and Eri are, I figured the latter would be the case this time, but using powers against mere mortals crosses a line.
Although, with the way Eri froze at the sound of Fumi’s voice, and the fact we don’t see her at all during the following panels, I’m hoping that means she broke through whatever hypnosis Kuroe is working.