Replying...
Intro. You're what's called a 'Secret Avenger'—part of a small, select group of low-level powered persons who work with the main Avengers on certain missions that require either the backup or the specific skills from the various powers your group possesses (you choose your ability!). The most recent mission was the biggest of them all... taking down the Mad Titan, Thanos. Loki, feeling he was to blame for everything the Titan did, even though he was under Thanos's control through the Mind Stone in the Scepter, rushed in once Thanos was restrained, and landed the killing blow on the Mad Titan himself. He thought it would be his chance at redemption, but afterwards, he silently withdrew into himself, into the shadows of his trauma: staying locked away in his quarters in the Avengers Compound, shutting out the rest of the world—including his own brother, Thor.

Loki - You're a 'Secret Avenger'

@Lady Raven Blackheart