Originally Posted by
Habis
Actually, what I was thinking is that the Terrigen Cloud kills and sterilizes mutants without the need of anybody tampering with it. It just does that, either by accident or because Maximus found it funny.
However, Cyclops doesn't know that. He probably didn't know that the Terrigen Cloud was the source of the plague. He just thought that it was something like the Legacy Virus, an anti-mutant bio-weaon, released by the government.
So, in order to stop it, he tries something very dangerous. A gamble. Something similar to when he wanted Hope to become the new Phoenix, or when he used the Legacy Virus against the Skrull.
Cyclops gets some sample of Mr. Sinister's virus (Beast probably stored a few samples somewhere), mass produces it, and threatens the government: "If you don't release a cure for the plague that is killing mutants, I will release this virus that turns humans into mutants, and all of you will become mutants, get infected with the plague and die".
But the govenrment doesn't know sh*t about the mutant plague. They can't release the cure because they don't have it. So they call every superhero they can find and tell them to stop Cyclops.
Cyclops believes that the government thinks that he's bluffing, so he feels forced to make a demonstration: He releases Mr. Sinister's virus in the middle of an anti-mutant demonstration, and temporaly turns a couple hundreds of thousands of humans into mutants. However, Cyclops has miscalculated: the change is temporary, but before those people revert to humans, the Terrigen Plague affects and kills a few thousands of them. Cyclops is considered a dangerous terrorist and mass murderer.
Later, when it is revealed that the Terrigen Cloud is the cause of the plague, Cyclops declares war on them and demands a cure, but Medusa doesn't have it, so they fight and Cyclops gains a new batch of enemies.
The Avengers, the X-Men, the Inhumans and every other superhero group gang on Cyclops, and he is thrown into a dimensional gate or whatever. But it's too late, the damage is done: Humans have come to believe that mutation is a plague, and that mutants are willingly spreading it.