Walkthrough: After getting a ride from Seafolk Village to Exeggutor Island, it is up to you and Lille to find and obtain the second flute in order to help summon the Cover Legend to help find Lusamine. The Island is an old Trial Site, but now is a place where only a few Wild Pokemon can be found. It also rains on this island quite often. At the end of the Island, you will find the Flute you are looking for.
Wild Pokemon:
Wild Grasses (Levels 40-43): Exeggcute(40%), Pelipper(30%), Exeggutor(20%), Gastrodon(10%)
Weather Battles (Levels 40-43): Castform, Sliggoo, Castform, Castform
Trainers: There are no trainers found here.
Zygarde Cells: There are no Zygarde Cells found on this island.
Items:
Prism Scale - North Island
Heart Scale - Hidden Within Red Flowers to the North
Big Pearl - Within Small Cave (Hidden)
Moon Flute - From Pedestal