Serenity Isle is just a quick boat ride from Oceanview City. Here, the player can visit the Fusion Resort, enter the Lighthouse Challenge, and battle against the second gym. To receive the dirt badge, the player must defeat Terry, the ground-type gym leader. At the top floor of the Fusion Resort you can teach any of your Pokemon Spore (Grass/Sleep/100%) and Leaf Blade (Grass/90/100%.)
The lighthouse hosts a challenge in which you go up the 9 floors of the lighthouse, with a trainer on each floor (excluding the final floor.) It is possible to leave anytime you want, although you end the challenge and must restart if you leave. Once you make it to the final floor, a man will give you an Eevee.