The Arc Reactor's structure itself had not been altered, because changing the foundational rules of reality would bring a series of problems, and the consequences of those problems were too great for Mephisto to welcome. So he had merely made Stark "miscalculate" a few parameters.
That alone was enough to cause all kinds of accidents with every Arc Reactor, perhaps even major safety incidents. Once the Arc Reactor's safety was proven unreliable, Stark Industries' stock price was doomed to take a steep dive—perhaps even more violently than when Tony had announced that Stark Industries was withdrawing from the arms industry.
Yet that was not the most immediate crisis. The reason was simple: Avengers Tower was about to collapse!
[According to calculations, the collapse of Avengers Tower will cause...]
"I can calculate it myself!"
[Based on the current circumstances, this system reserves judgment regarding that assertion.]
The explosion in the middle levels of Avengers Tower had nearly melted through the entire building. If left alone, the tower's entire upper half would come crashing down.
But if he dealt with the problem in the middle levels, there was no telling whether the even larger Arc Reactor at the base of Avengers Tower would explode. If that thing went off, forget Avengers Tower—there might not even be a Manhattan left.
So Tony did not try to have it both ways. He charged straight into the bottom of Avengers Tower.
At that very moment, Strange teleported in as well and examined the enormous Arc Reactor before him, whose brightness was clearly abnormal.
"No, no, no, magician. Let's be clear—this isn't your field. It's mine."
"I know, Stark. I'm only here to remove any interference for you."
As Strange spoke, he cast a spell, using magic to support the entire Avengers