I suspected as much, but the author did a great job making the reader unsure of young Cero's demeanor and intent. Too many stories get lazy spoonfeeding the meta.
Her abbility, kamuro, one that can make her slice through space and time is the main reason of her outburst. That abbility side effect is making her so aggressive. So in order to revert her to her original personality, he need to find a way to take away kamuro from Hana.