Mega Dark Force with The Mega Demon Costume ! Haha, this looks very cool. It surely has the MEGA look to impress and maybe scare your friends (or anyone!). You can get it at Costume Discounters (and see a bigger picture which shows you the hands with more details, very good). So here is this long robe with high collar and oversized mask with horns, hairs and goatee.
One of the costume that makes an impact when you come in any room.
Or see it at Buy Costumes.