Once Yuga falls, a cutscene will occur and Link will receive a new power that lets him merge into walls. To use Link’s power, walk up to an applicable wall and an icon that says “Merge (A)” will display near the bottom-right of the top screen.
Press A and Link will merge into the wall; while merged, Link can move left or right across the wall, provided there are no obstructions. Press A to emerge or “exit” from the wall. Note that merging drains your energy gauge; when the gauge runs out, Link will automatically exit the wall.
Before using the power, don’t forget to grab the nearby Heart Container , to increase your heart count by 1. From where you are now, merge on the wall to your left and walk right toward the gap in the wall (where Yuga left the room).
Link will squeeze past the gap and appear on the other side. Keep walking right, while within the wall, and you will find some rupees waiting at the end. Return the way you came to the boss room and merge on the wall to your right instead. Now walk left, through the gap and continue going left until you find a Blue Rupee.
Next, hug the barrier to the right and walk up and right at the same time, to drop down diagonally. Go right for a chest containing a Silver Rupee, worth a whopping 100 rupees. Nice! Afterwards, head left, toward the tower’s wall and merge into the wall.
Now walk right, to the other side of the tower. If you messed up the diagonal drop, just merge to your left and walk right to reach the other side. Then, while on the other side, merge to your right and walk left to get the Silver Rupee chest.
On the left side of the tower, head left to find a platform lift. Step on it and go down to the next screen. Continue down and you’ll notice the floor subsiding into the wall, revealing a very long drop below. Not good for your health!
Quickly merge to the wall on your right. Then emerge when it’s safe again and continue your way down. At the end, step onto the platform lift and head right to reach the next screen.
Here, there will be two swinging platforms. When the left platform is next to you, merge onto it. Then wait for it to swing and meet up with the right platform; once this happens, walk right to the right platform. After the right platform swings, emerge and you’ll be on the other side.
From here, go right and, once your gauge has replenished, merge into the wall directly on the right. Then walk left and emerge for a chest containing an impressive 50 rupees.
Go back across the chasm and merge into the same wall; then walk toward the direction of the gap in the wall to return to the entrance of the dungeon.
From the entrance, head towards the right side of the room and you may notice another gap in the wall; merge on either side of the gap and go through the gap to find a chest containing an amazing 100 rupees. After you’re done, leave the Eastern Palace via the entrance to the south.