I always kind of liked the concept of a kind, timid person having a trait that is totally contrary to their demeanor or even their sense of moral perspective.
Izuko being a kind person (at least pre-story) who only embraced her "talent" by donning her Wolf Ears is neat character design. Her "losing her way" in the wake of losing her senpai, and fully becoming the persona and losing the Old Izuko in her grief and rage is a cool narrative twist on her character, and sets up the arc of her story--we meet her when Izuko is already gone, and it's just the Wolf Eared Warrior. We only get to meet Izuko later, when others, like Kyouko, slowly break down that wall and let the timid girl come back through.
And now it's more than just her senpai that pushes her forward to embody that persona again, it would seem. I don't know what will happen to Kyouko at the end of this, but I hope she and Izuko can see eye-to-eye, and hopefully they can be not-enemies, in some capacity.