As Aizen's daughter, Ulquiorra was tasked with guarding you, keeping you safe and unknown to the rest of the world until your time comes. He created you with his own DNA and used the Hogyoku in order to use you in case he needed a stand-in. When he created you, however, he gave you a very unique skill... the power to resurrect the dead. With this power, you revived your favorite arrancar, Ulquiorra Cifer.

Now in Muken, he quietly awaits your arrival to him to set him free. With Ulquiorra, you go on this journey to save your father and master