Zayn couldn't believe that damaging the Core of the Undead was not enough to defeat the Undead, however, that was exactly what happened right in front of him.
The Skeleton's movements were much slower than before but it did not magically empower Zayn to face its headbutt head-on, quite literally. His skull would break which was why his body reacted instinctively as he pushed his feet against the intact part of the skeleton's ribcage to increase the distance between himself and the Skeleton's head.
He was still gripping the silver iron shortsword tightly in an attempt to deepen the cut in the Core of the Undead as the blade was pulled out of the Skeleton by force.
