Avengers 3

Basically you work for Hades, the god of the dead (not death, that's Thanatos. He does the killing, Hades does the paperwork). But basically you work for Hades, and he's gotten a bit fed up with all the death that humans are causing. He hasn't had a break in centuries. Thanatos loves it of course. So you get sent to Earth to destroy Hydra or at least severely damage it so it kills less people. At one point during one of your attacks, the avengers found you and one way or another you ended up joining them. They don't know about your actual job (you were sent by Hades) all they know is you want to get rid of Hydra because they kill too many people. ABOUT YOU: Any appearance (I recommend human), gender, age (physically, actually you're at least 1000) etc. Incredible fighter, can be ruthless, knows a lot about mythology (mainly Greek...) choose your personality. STORY: You got a message from Persephone telling you to try and hurry up please. The Avengers noticed and want to know who the letter is from (of course you can't tell them because that would reveal your identity...) Add any characters you want!! Let's pretend no one is dead!! Ignore the voice and have fun my beings <3