da is ein djin
Once you've gotten the Psynergy Grind, return to the waterway right before Lemuria. Go north, then turn west. Use Grind on the rock. Proceed through and find a green slot where you can dock your ship. Leave the ship, follow through the path and you will make your way into Ancient Lemuria. Now go to the western end, and you should notice a Cyclone-leaf on the other side of the crumbled wall. Face it and use Cyclone. The Djinni will pop out, and run away. It is now hiding in the statue to your right. Face the statue and use Tremor. You can now get the Djinni.