Superman and Thor (if he doesn't use the OF) would give him the biggest problems since their powers are innate. In the Takion mini it was said he can't manip innate powers, but cosmic or external sources are all subject to his manipulation (in fact Superman was used as an example).
So CM gets turned back to Billy. Nova's powers are turned against him and he subdues BM.
Hercules just isn't mobile enough to be a difference maker.
It comes down to Supes and Thor vs Takion based on his few showings (stopping time, slowing down the god wave, being said to surpass Highfather in terms of power, owning Insane Lightray). In fact the guy can't be hurt by anything short of the really esoteric. IM killed him but we have no idea how he accomplished that except that he was empowered by the Source to fulfill said task.
The dude doesn't even have weight or substance. He has no mass or molecules of matter and has less substance in the physical reality than light.
And I forgot to mention that SS' portion of the Power Cosmic would also be manipulated against him.
Ehh! Check the definition of innate. His power is tied to his natural physiology i.e. what he was born with i.e. innate gifts. The sun unlocks whatever power/synthesizing process that is trapped within his cells. The amount of energy he actually absorbs from the sun is negligible.
The idea that he's a solar battery is wrong, the sun simply doesn't give him enough energy for his power - if he was a solar battery he'd have to sun dip constantly to get the desired energy levels.
Anyway there was a comic that showed how his body makes energy - nuclear reactions at a cellular level.
Thor is also born with his gifts, strength, durability, affinity to lightning. He doesn't draw his power from Gaea.