I had a whole team built around Dr. Manhattan, being that he can make ANY supervillian you throw at him not exist. Not kill them by any means, just erase them.
SO since NMA is living up to his name, its time for a back up plan.
Luckily, she can do the same things that Dr. Manhattan can do.
My Pick:
Pheonix [Jean Gray] - Xmen
Phoenix is an Omega-level mutant. Jean Grey-Summers is one of the most powerful mutants who ever lived. She has great control over her incredibly powerful telepathic and telekinetic abilities. After the Phoenix Force became one with its true heart and soul in the human form of Jean Grey, whose mind serves as a nexus point for all realities, Phoenix was able to tap into the vast powers from the sum of all life (the Phoenix Force); hence, her own powers were augmented to an unimaginable level and she became capable of controlling and wielding the incredible powers of the Phoenix Force. She can create and control flames at will (Cosmic Pyrokinesis), as well as control matter, energy, and thoughts completely. She also can resurrect herself after death. Please note that Phoenix is able to generate cosmic flames which are not dependent on oxygen. Her fire and flames are created either through cosmic energy or by her ability to stimulate molecules which generates heat. Therefore, Phoenix can manifest fire independent of her environment even under seemingly impossible conditions such as underwater or in the vacuum of space.
Thing is, she's kind of nuts. Honestly though, she is unconquerable.
Also, this is not the movie version. Just an fyi.