As the fight continued, the situation wasn't looking too good for Shiro. Her MP was barely holding on even with all of her skills that boost MP regen.
Celestial Rune Kara, Element Field Affinity, Mana leach and several others that she's applied to her armour on top of mana coils that gather the ambient mana. All of this wasn't enough to balance out the amount of mana she was using to keep up with the boss.
While Yin and Lisandra were able to damage the boss, it was barely able to dent his HP bar.
Unfortunately for Shiro, she couldn't fly into the air either as the boss clearly demonstrated that he had the ability to ambush Yin and Lisandra if she wasn't keeping him at bay. By doing so, it increases the chances of those two dying to the boss.
