The action of resurrecting her friends drained Ria more than anything else she had ever done in her life. Manipulating materia prima in such large quantities and with such precision and accuracy wasn't easy. If not for the fact that she was accustomed to wielding a spark of it in battle, she would not have succeeded even to the extent that she had.
It took every ounce of willpower and control that she had. It took all the concentration she could muster, diverting all of her attention towards the sole task of resurrecting her friends.
Reversing the autolysis and the coagulation of blood was not easy, but she painstakingly reversed much of the process, undoing the chaos of death that had begun to consume the otherwise pristine order of life.
However, the Second Law of Thermodynamics stated that the entropy of a closed system increased with time, making it more complicated for her to drastically reduce the entropy from the returning bodies of her friends.
