I figured build flaws into the character via the backstory to add room for development. This way the character has reasonable existence, but can't mary sue because of circumstances in character development.

I actually like that idea. Thanks Raptor!

Good basic idea, but I think I can fix it so it doesn't fall into Mary Sue territory.

"An adroid designed by Dr. Gero, she was meant t oserve as Cell's leash to keep him from turning on Dr. Gero. Since her AI was incomplete(a timetable of 15 more years to complete her AI functionality), and Dr. Gero's death, she's only aware of her mission, as a final contingency against his androids. She is in short a clone of Dr. Gero enhanced with android enhancements. His brilliance retained, but not Dr. Gero. She's the anti-android protocol that faild before it could even start use."

That way, you have room for character development. ^_^

*Ordinary fanfic protagonist*