While her nightmare was some cute horror, recalling to chapter 1 itself pretty much explains why she's so insecureErio has hinted at it before, but she must really be deeply and genuinely insecure that all she is to Ange at the end of the day is a battery. And she can't even picture "her" journey without Ange so the insistince that Erio can continue "her" journey as opposed to "their" journey together hits extra hard tbh