Speak with Deo, then head right to the next screen. Keep going right, up the broken stairway. When you pass the ruined herb shop, head down and to the left and bring along the rock on the ground as you stick to the bottom path and go right again. Use Vortex along with the rock to break down the wooden barrier, then enter the Abandoned Village to the right.
Here, head right and pick up the plant if you want. Keep moving right while going down, and when you reach a dead end, use the plant or cape along with slipstream to make your way up, past the enemy that can eat Toku, then up and to the left past the crab enemy. Now, gust off the edge, then guide Toku (using the cape) with slipstream around the protruding edges and up to land on a backwards L-shaped platform. This might take a few times to get right, so don't worry if you fall.
From here, gust up and to the right, then keep heading right to enter a new room. Head right, then down past the glorb spawning enemy and crystal until you reach a rock and a wooden barrier at the bottom. Use Vortex and the rock to break the barrier, then head right until you reach a pull-switch and a crab enemy. Pull the switch, then head right again until you reach another wooden barrier. Use Vortex with either the crab enemy or a regular glorb to break the barrier, then head back left a bit until you can go up and to the right.
Keep moving up, and stay in view of the right wall until you can see a Resonance ball along with a smoldering torch. Gust the torch, then use Vortex on the ball to break the cracked floor below it. Then, slipstream burn the vines below and gust the Resonance ball down the hole.
Head back to the wooden barrier that you broke on the bottom right. Step on the pressure pad to the right, then gust the Resonance ball through the now open door. Go up to it, and take it with you up and to the left. Pass the group of enemies, the use the Resonance ball along with vortex to break this wooden barrier. Then, take it along down and to the left, until you reach the crystal. Use Vortex on the ball in the air near the crystal, the path to the final chest will be shattered open. Open the final chest to release Deo's last hidden memory. Then head right, then up and to the left back the previous screen.
Go left until you can fall down, then exit the Abandoned Village to the left and return to Deo.