Not a mutant, they were tested by Mutant Jesus himself, Cyclops
They use to do little shit like that in stories, but not anymore. I love the shots of people worlds away reacting to 2 heavyweights throwing down.My favorite moment in the original story is late in the game against Thanos Earth has been blown out of the sun's orbit, has entered a new ice age, and its cosmic protections have been blown, causing Annihilus and his army to come pouring out of the Negative Zone and they take over the Earth. And this is all in one panel and is never brought up again because it's just complete small potatoes in terms of what is going down with Thanos against the cosmic beings.
(and everything Thanos does is undone anyway)
The Celestials were throwing planets at Thanos. They just lined up a bunch of planets (some of them apparently populated with people?) and just used them as ammunition.