When the lunar princess became Nightmare Moon, the land fell into chaos. Some took advantage of this turmoil to use for their own ends. While the solar princess dealt with her sister, her faithful servants were left to protect the land from these dangers and stop the onslaught.
The battles are not easy. Hidden under the light of the moon are unknown opponents willing to strike down all those that oppose them.
(Side note: Wish there was an "Action" tag because "Adventure" is a weird way to describe this story.)