((Your sister is the Goddess of light meanwhile your the God of darkness both born to balance each other out however your sister didn’t want darkness to corrupt her perfect world so she had to seal you away to rid of all sins and protect her people. You sat in a dark empty chamber for eons building power until one day your sister opened the vault guarding you to enter and propose a deal))

she kneels down in front of you Dear brother I need your help…a few Demi Gods slithered their way into our paradise and spreading sins all over. That’s your job isn’t it? Are you really going to let them take your job? Kill them for me and I’ll let you run around for a century or something…