granted spectre is much more powerful, however Shazam took on the spectre in shazam's seat of power which was the only reason the fight lasted more than two seconds. anywhere else and that fights ends extremely quickly. strange has fought mephisto in his own realm and won. pointing to the spectre fight is troublesome because shazam was only able to hang in their because of the location of the fight.
but strange has had pleanty of experience against opponents who had nigh omnipotence and omnipresence. how would that be the deciding factor against strange?
the fact that shazam is part of the quintesant does not mean that strange cannot hang. strange has hung with death and other beings that are rather high on the food chain. what could shazam do to strange? strange has taken on multiple foes with abilities similar to shazam and he has won. being a member of the puintesant does not make you unbeatable. strange wins 6/10 or 7/10.
Shazam typically has more power at his disposal than base-level Strange does. Shazam has the power of numerous gods at his disposal from the get go. Strange has to seriously power-up to achieve the level of power that Shazam has all the time.
However
Given the scenario presented here, Shazam has no chance whatsoever. None. Nada. Zilch. Strange benefits from preparation moreso than any character in comics, and I'm including Thanos in that estimate. Strange could've become omnipotent 10 times over in the timespan presented in Thanos-Quest. The scans of the Shuma-Gorath battle don't really do justice to the magnitude of that victory. Imagine that he took out one of Lovecraft's nastier alien menaces and assumed it's power, if that helps. Strange had abdorbed so much magical might that if he had returned directly to our world it would have been destroyed like a moth in a bug-catcher. There's almost no one that Strange couldn't defeat with a week 's prep. If nothing else, that's enough time to cast the 7 Gates of Chaos and destroy the universe.
In an unprepared fight on neutral ground, I'd say Shazam 3/5. If they were on the Rock of Eternity, I'd go up to Shazam 4/5. Strange still gets the 1/5 if he can absorb Shazam's energy. If he could execute a Conjurer's Sphere within the Rock, Shazam would be done, but that's a difficult move and one he seldom uses.
The scenario proposed is not a fair fight.
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it is a shame. i started this thread really wanting to know what people thought about these two going at it. two of the most spectacularly magical people in the two universes and this is what one gets. shame