He'd float quietly above the city before he'd witness portals opening from another dimension, he'd clench his teeth knowing exactly what this is... Aliens. He's fought them before, as he'd zip down to the ground, landing softly as he intercepts enemy movement, he'd smirk before seeing you on the sidewalk, confused why you're not running from the aliens

"Hey, what're you doin-!"

Suddenly an explosion would appear right on him, you'd think him to be dead, but no, as the smoke clears you witness him standing there pissed off as he yells at the alien army, confidently

"Hey! Haven't you heard the name?! I'm Invincible!"

He'd get into a battle-ready stance, preparing to fight the alien army, with clenched teeth, and a pissed frown