Legend of the ten suns
Version 1
There used to be ten suns who took shifts and worked only once every ten days. One day, for the lols, all ten of them decided to come to earth on the same day. As a result, all water sources on earth evaporated and dried up.
It also turned out that the ten suns enjoyed watching people suffer, refused to leave and humanity had no night. Finally, one archer snapped, went on a quest to obtain 10 sun-slaying arrows, shot down 9 suns one by one and threatened the final sun with the last arrow. From that day on, the sun would always rise and fall according to the same schedule.
Version 2 had the suns being controlled by some evil god who wanted to destroy humanity, and the archer had to choice but to shoot down 9 suns.