Guardians of the Galaxy's Star-Lord Could Easily Defeat Superman
In recent issues of Marvel Comics' Guardians of the Galaxy from writer Al Ewing and artist Juann Cabal, the Legendary Star-Lord has evolved to the point where he could easily take down DC Comics' Superman. Having been trapped for nearly a century and a half in a time-displaced reality, Peter Quill returned to the primary Marvel Universe as a literal Star-Lord, wielding immense power at his command and channeling it through his element guns. But it's the precise nature of Peter Quill's powers that would make him perfect to fight the Man of Steel.
Star-Lord has become the Master of the Sun, slowly awakening to the fact that perhaps he, rather than his weapons, is the true power. This occurred after he siphoned away the power of the Gods of Olympus in a bid to save his friends. The resultant explosion appeared to kill him, but instead sent him to Morinus, a realm in another reality where Quill was able to develop his new powers for nearly 150 years before finding a way to return home (with the angry and vengeful gods in pursuit).
However, during this period of evolution, not only did Quill become immensely more powerful and full of cosmic power, but he practiced channeling it through his unique element guns to create incredibly varied elemental effects, from generating raging winds to casually synthesizing various natural substances. Peter now has such control of his powers that he can sculpt with the guns' element-generating abilities, able to create a peridotite statue despite having only passing knowledge of the minerals involved, as seen in Guardians of the Galaxy #9. Not only does this suggest Star-Lord would be capable of generating Kryptonite or Nirodhium with the element guns' 'Earth' setting, but that his dawning awareness of his almost limitless power would allow him to do so instinctively when faced with a Kryptonian threat. But being able to quickly and skillfully create substances that can de-power and kill Superman isn't the only thing that makes Quill a match for the Man of Steel.
Becoming Master of the Sun has also unlocked a new relationship between Star-Lord and light itself, as shown when he effortlessly shot down the King in Black's dragon in Guardians of the Galaxy #10, which was fashioned from the primordial void. Coupled with the element guns' ability to absorb the energy of powerful individuals, and the fact that Superman's powers come from yellow sunlight, Peter could effectively drain Superman's energy while using it to generate the substances which hurt him the most. Either power would be effective, but combined Star-Lord is able to generate the materials needed to defeat Superman from a process that in and of itself could defeat Superman.
It's funny to think that this particular "Who Would Win?" argument wouldn't have even been a question a few months earlier. If Star-Lord was still the roguish outlaw of the Guardians of the Galaxy, it's likely Superman could take him down without a second thought. However, the Master of the Sun version of Quill is a whole different matter. Quill is now harnessing the power of cosmic gods, limited only by his willingness to open himself up to his own potential. If DC and Marvel ever clash again, the Avengers should allow Thor to stand back and let Peter Quill be the one to take down Superman - not only would he win, but he'd end their battle back at full power.