Higana still being "in there" and not having her ego fully subsumed/erased was the key point, I suppose.
Which, I wonder if Yue considered that angle, given I assume she left Higana intact so Izuko would be hurt that much more.
But that also means that Higana could do...well, this. And Yue doesn't seem stupid, meaning she could account for that sort of betrayal, I'd imagine. Curious.
Can't wait to see how this all shakes out in the final fight, and who is left standing (and what becomes of them).
Thanks for the TL.