Xavier is far more dangerous to more people in a given time frame, but he could potentially be bombed to shit.
While Superman is virtually invincible to human weaponry. You'd have to set off a nuke and hope it both hits and he doesn't recover with the Sun afterwards.
I'd go with Xavier, he could right from the start attack every single mind on Earth and kill them slowly as seen in X2.
Overall Xavier is the most dangerous. He could end the world in a few minutes. Just make everybody launch all their nukes at once. As badass as Superman is, that amount of damage would take years for him to reach and even then it wouldn't be an apocalypse like that. His heat vision wouldn't make the world unlivable for future generations.
I'm going to say Xavier. Assuming he goes the direct kill route, I think it would be difficult to mount any kind of counteroffensive. As shown in X2, the people he targeted weren't just dying. They were incapacitated by pain while it was happening, which makes it virtually impossible to actually try and retaliate.
__________________ Never take life seriously. Nobody gets out alive anyway.
The one who can instantly contact billions of minds as of Apocalypse
__________________ "Happiness is a lie. Life is horror. The light is always dying all across the universe. The last star will flicker out someday, when it does, all that remains is shadow. And I will be its king!"'-Amahl Farouk
Superman starts throwing large objects at the earth at super speed inside the atmosphere extinction level event time almost instantly. Try stopping it... Xavier just thinks, either way everyone dies...
Of course if his heat vision can get to 15 million Kelvin he can turn the atmosphere into a fusion reactor. Tsunamis, earthquakes etc at Superspeed are also options. How about the old Supreme Power dive bomb tactic the maths seemed solid in that. Extinction level event again. So many options.
Superman's heatvision is usually said to be around as hot as our sun, so just under 6k Kelvins
Not sure if the DCCU has been consistent on this though. He did burn-cut right through a Kryptonian ship and their tech is far more durable than anything on Earth.
Superman can just fly through the core of a planet to destabilize it.
X on cerebro could probably make everyone commit suicide.
So...draw?
I remember a Superman story where he faced a bunch of elementals and he just said he'd render the planet uninhabitable if they persisted, and he was being kind them.
I guess Charles would be more sinister, he could do more than just destruction
__________________ Chicken Boo, what's the matter with you? You don't act like the other chickens do. You wear a disguise to look like human guys, but you're not a man you're a Chicken Boo.
Okay I guess I responded as if this was comic supes my bad lol
yeah movie versions, rogue prof x is worse. movie supes cant render a planet useless
__________________ Chicken Boo, what's the matter with you? You don't act like the other chickens do. You wear a disguise to look like human guys, but you're not a man you're a Chicken Boo.