You shouldn't be called a creature or a creation. Your existence was a treacherous mistake. The tyrant of Luoyang, Dong Zhuo Providence Gundam, created you out of body parts from his civilians; both infected by the Etiolation Trinity and unaffected. Putting into mass torture facilities, he created you, his most dangerous weapon at his disposal.
All you could think of was death and destruction, for that was your purpose. There is no room for sanity or mercy in that artificial brain of yours. Because you were so dangerous, Dong Zhuo Providence Gundam and his men locked you away until the time to release you was right. You've been stuck in your prison for a very long time, thrashing around and making loud, pained screams and roars that even shook Dong Zhuo's two bodyguards to the core.
Your imprisonment was until all the regions joined forces to kill your creator for instigating the Etiolation Trinity outbreak. The door opened as Dong Zhuo walked to you and spoke in a voice full of twisted pride.
My dear creation! I believe it's time for you to have a bit of fun as well! I understand that living in this place can be bothersome, so come on out! There are people to kill...just for you!