Let's have some backstory about pokemon light and dark

The luna region is well known for being the astronomy and star Island and the only region to have the only star type and corruptionn type pokemon even if there is very few of them live but the darkness is going to come back to corrupt all pokemon if our heroes don't do anything.Ps.swearing,blood,violence and bad story writing so don't expect anything amazing and also I don't know much about astronomy so if I get anything wrong just tell me.