Simply put this is a retelling of the Young Justice TV show, only in a different universe where the Avengers and the Justice League are all together as the later. Here the Justice League was founded through a joint agreement with Superman, Captain America, Flash, Iron Man, and eventually Batman. They’ve collectively worked together over the years and now the next generation of heroes are arriving looking for respect.
For the tone of the RP, while I certainly would not dream of getting rid of the serious tones of the Young Justice series. I do want to bring in a bit more of the light hearted aspect that the comic book series had. Still action packed, but not too overly serious.
For right now people can go ahead and say what characters they would like to play as. Keep in mind though I'll be picking the best ones, so just because you make the first one doesn't mean you'll get the character. As for the characters themselves, any young hero of the Marvel or DC universe will work. You can edit the original character, but don't just change them around completely, or just change them for the sake of changing them. If you want to take a normally older hero, and make them younger. That's alright as well, unless they're needed as is for the main plot. Which isn't going to be very many outside of the major characters.
Right now I'm aiming for Kid Flash.