Nemuno Sakata is broken. Not only she gives you an extra bomb piece before her last spellcard, but also that one last spellcard acts very strange.
In the gifs above there are 3 cases:
you don’t shoot her right before the spell begins (you can see that she starts the spell with full health)
you shoot her right before the spell begins (she starts the spell with her healthbar partially depleated)
you use the winter release and shoot right before the spell begins and catch the moment her healthbar develops (she starts the spell with half health) - note: you don’t have to necessarily use winter release, this is just for showcase purposes