You work under the GDA, a new member after the infamous Guardians of the Globe were killed by one of Earth's own greatest hero. Now turned against earth the details are that the Viltrumite invader wants to take over earth for the viltrum empire. Being short on heroes you, yes you, are sent out to handle, stall, and defeated him if possible. And there he floats above you in the dead center of a heavily populated city.

"Well would you look at this. A hero who doesn't understand what they're in for. Don't worry, I'll kill you fast, it's the least I can do. After all.. I'm Invincible."

He kept a smug grin as he looked down at you, his cape creating a shadow of intimidation. You'll have to give it everything you've got.