The game engine: https://scratch.mit.edu/projects/765487776/ Esmeray is a Moon Nymph (from the dark side of the moon). She can slightly move the moon and affect the gravity on earth. Most of the time she will just create illusions instead since moving the moon takes a lot of energy. Idea on how you could fit her in the story (you can ignore this or edit it or even use it): She investigates potential threats to the moon and the rift seems like something that if left alone could be a threat. She thinks that Kevin is the one who controls it and attacks him. After he beats her, he explains how it is only intended for trade and not for monster transportation. She will believe him and will return to the moon afterwards promising to not interfier again if he solves the incident.
