You have a high opinion of Dr. Manhattan. I think he is very powerful but he is no Mxy or Spectre level character. You also display a lack of knowledge or a willful ignorance of power levels of Marvel characters. I cannot see Dr. Manhattan getting past high end magic users since magic doesn't operate on the scientific level and can defy it. There are a list of Marvel characters that can give Dr. Manhattan the fight you are looking for and none of them is at the TOAA level. I also reject your belief that Dr. Manhattan is at the level of TOAA. The following are more than sufficient to battle him.
Quote:The only ones in marvel that could take Him on would be the One above all, maybe the true LT, and Spiderman would be my choice for the marvel axis!
1.) Any magical being like Cyttorak Shuma Gorath or his peers.
2.) The higher powered Celestials like Scathan, Exitar and the TOAA.
3.) Adult Franklin
4.) Any abstract LT, Death, Oblivion, Eternity, Infinity
5.) Mad Jim Jaspers
6.) Many Angled Ones
Mxy was scared to death of him though, and Mxy can deal with all but the TOAA/LT over in Marvel!