Zeshin returned to Los Noches and knelt before Aizen, "The deed is done, my Lord. I stabbed the one you mentioned right through the heart."

“I see.” Aizen stood from his throne stepping toward Zeshin, “Would you like to become a fraction, Zeshin? I have the perfect master for you,” a smirk crossed his face.

Aizen stood in front of Zeshin; he was pleased with what had transpired in the mission he sent him on. Now he just needed to make sure Zeshin stayed in his arrancar state of mind. Assigning him a master just might help. He waited for his answer.