The Phantom Stranger possesses a variety of magical abilities, such as concussive magic blasts, levitation, teleportation, etc. His power is so great that it is said that he is almost as strong as the Spectre.
Superman wins easily. Superman's physical attributes are far superior to that of Quasar's. Supes has the ability to flight at speeds that transcend the speed of light, thus making it unlikely that Quasar will even catch him (with a physical assault or an attempt at draining his energy). Superman has shown to be strong enough to KO much more durable oponents with a single punch, thus making it pretty easy to end the battle quickly. In closing, depeding on which version of Superman you have, he can manipulate the electromagnetic field, thus precluding Quasar from taking his solar energy.
Thor destroys Kid Flash, due to pure, unmitigated power. KF could theoretically enter the speed force, accelerating past light speed-to get away, but would be unable to beat Thor. If Thor goes all out, he could destroy the planet, in which KF's only escape would be to transcend a dimensional boundary.
The Spectre is the manifestation of God's wrath, and DC/Marvel have an unwritten rule that Judeo-Christian Gods reign over other gods (e.g. Thor). The Marvel demons, which are inferior to the Dc/ Marvel gods, would lose to this judeo-christian manifestation of God.
On the Marvel side, we have Ronan the Accuser, Gladiator, Thor, Beta Ray Bill, Quasar, Blue Marvel, Silver Surfer, Nova, Hyperion, Hulk, Ikaris, Red Hulk, Sentry, Skaar, Doctor Strange, and Phastos and on the DC side, we have Superman (15,000 yr. old version from the 853rd century), Kal Kent, Icon, the Spectre, and the Phantom Stranger. Who Would Win? Write with passion, but limit the number of insults.