To find the Lizalfos Lv. 3 Echo in The Legend of Zelda: Echoes of Wisdom, follow these detailed steps:

1. Location: The Lizalfos Lv. 3 Echo is located in the Faron Wetlands, specifically in a cave system.

2. Accessing the Cave:
– Start by navigating to the southwest corner of Faron Wetlands.
– Look for a small ladder leading down into Cave 1. This is your entry point.

3. Navigating the Cave:
– As you swim downwards, stick to the left side of the cave. You will encounter Bio Deku Babas, which can be cleared using a Bombfish Echo.
– Continue swimming and follow the cave path, taking time to breathe in air pockets and bubbles.

4. Encountering Armos:
– You will encounter an Armos, a living statue that can only be damaged from the rear. To turn it around, use L2/X to grab it and hold it, then release it. This allows you to attack its back.

5. Moving Through the Cave:
– Travel up past the Needleflys and down around to the right. A boulder blocks the way here.
– Grab the boulder with L2/X and drag it left, leaving the water and going up and over into the left pool. Set it on the ledge above where it was.
– Below, dislodge the rightmost boulder with L2/X and move it to the right. Move the left boulder to the left into the pit.

6. Reaching the Lizalfos Lv. 3 Chamber:
– Continue into the next room, where you will find a boss-like encounter with a Lizalfos Lv. 3.

7. Defeating the Lizalfos Lv. 3:
– Use Armos Echoes to repeatedly stun the Lizalfos. While it is stunned, whack it with your sword. The Armos Echo will attack the front of the Lizalfos, temporarily stunning it.

By following these steps, you should be able to locate and defeat the Lizalfos Lv. 3 in The Legend of Zelda: Echoes of Wisdom.