Before you set out of the house with Lyll, you will need to collect (or purchase) her Mattock. Refer to the guide for Xemn's area to learn how to collect it. You will need it for just about every useful operation that Lyll can perform. Having a pair of Powered Boots is a plus, but if you don't have it yet, you will have an opportunity to collect them in Lyll's area.
Once you have the Mattock, there is nothing to prevent you from hunting down the shop that contains the Shield. This item will make a substantial difference in your fight against the Crown guardians. If you wish to find it, you will have to deviate a little from Lyll's usual portion of the dungeon. Before you begin, it's a good idea to collect the money bag from the treasure chest along the top of the dungeon if you have any less than 95 pieces of gold. At the dragon painting, go to the left instead, and smash the block in your way with the Mattock. Climb down the ladder to the level below. Whether you climb all the way down, or hop off the ladder early, you will end up dropping three more levels.
When you reach the bottom, you will see a ladder leading down to the floor below, and an otherwise unremarkable dead-end to the right. The blocks to the left of it contain stalactites, but the dead-end is clear. Have Lyll walk into the dead-end and smash the block above her on the ceiling. Surprisingly, an Inn sign will be revealed. However, you can quickly change that by jumping up into the sign. The Inn sign will be wiped away and replaced with a Shop sign. Once you see the Shop sign, push up against the dark behind you and you will indeed enter a shop. Inside, you will find the Shield being sold for an expensive 95 gold, along with the health restoring Elixir for an incredibly inexpensive 10 gold. It is good to remember this location in case you wish to purchase Elixirs. Trade your hard earn gold in for the Shield.
Now that you have it, you're only half finished. You still need to climb out of this pit that you've fallen into. There's no need to use up a Crystal. Simply climb down to the room below, and begin climbing back up the ladder immediately to the right. You'll have to climb up several stories before you reach the top. Once you are perched on the column at the top, you will see a tiny ladder segment to your left between you and the ladder that leads back to the dragon painting. All you need to do is walk straight off the left of the column. Continue to push left as you fall and you will "knock" into the ladder. When this happens, stop pushing left. Once you land, do not attempt to move. Simply jump from the position you landed on, and after your feet leave the ladder, push left and up. Lyll will grab hold of the ladder and begin climbing.
To enter Lyll's area of the dungeon, travel right from the dragon painting, and you will reach the ladder that leads to Pochi's area. Instead of climbing down, climb up the ladder to the platform above (guarded by a Slug), and jump up to the ladder in the upper right corner. You will enter through the red and white area near the center of the map above (near the location of the treasure that contains a Crystal). To get started, follow the upper path of the room and proceed all the way to the right.
When you enter the next room, you will have to dodge a series of enemies that occupy the floor and the ceiling. Run past them to the right, and drop down to the level below. Push to the left as you fall to access the platform near the top of the room. (At this point, if you would like to collect the Crystal from the first room you arrived at, jump up and follow the dashed line on the map back to the original room, but you'll need Jump Shoes in order to collect it unless you lure a Snake Kid all the way to the left and jump off of its back.)
You'll need to use the Mattock to break the block that prevents you from accessing the chamber below your feet. If you already collected the Powered Boots from Xemn's area, you can follow the directions on the map and take the shortcut down a few levels. Smash the farthest block on the left and drop down. Then begin pushing against the left wall, and you will smash through a set of illusion blocks and fall through three levels before reaching the bottom. Jump down to the next map to continue.
If you don't yet have the boots and would like to collect them now, avoid the shortcut and access the ladder in the lower right corner to the room below. There, you will have to unlock at least one door and smash a couple of blocks with the Mattock to access the treasure chest in the lower right corner. Inside, you will find the Powered Boots. From there, you need to unlock the door that leads to the ladder on the right, climb down, and make your way over to the ladder on the left.
Whether you fell through the shortcut, or arrived via the ladder in the upper left corner and unlocked the door, is it worth taking the time to cross this room and collect the treasure chest on the right. The problem with the floor of this room is that it disappears after you stand on it. They are not illusions, they just crumble, so you won't fall straight through them. That means if you jump the moment you touch down, you can bounce off them before the break apart. The treasure chest off to the right contains a set of 20 keys which will certainly come in handy. Then drop down to the floor below.
Be careful of the spikes near the top of the room. You can resist them if you push up as you walk along. It's not really possible to stay on top of them the whole way unless you jump, so it's fine to fall to the floor. The important thing is to reach the treasure chest on the highest block on the left side of the room. Inside, you will find the Fire Rod.
Once you collect that, immediately begin walking to the right. Pass through the corridor with the picture of Princess Celia and jump over the tall wall. Fall down into the hole to the right of the wall to reach the chamber below. Hop along the blocks if you can or walk along the spikes if you have no choice. (The spikes here turn into solid blocks after they hurt you once, so they're not terrible.) Once again, you want to leap up to the highest block on the left side of this room, and inside you will find Meyna's Wings.
At this point, if you do not intend to collect Lyll's crown, it's a good time to make use of a Crystal and warp to the entrance of the dungeon. If you do not have one, or if you wish to proceed to the crown, you'll have a bit of climbing to do. Climb out of the pit you're in, and head to the right. You'll see an "active" volcano in the background. From here, you must jump through a gauntlet of platforms and columns, until you arrive at a room that appears to be full of red and white blocks. You will soon discover that the red blocks are all illusions, and only the white blocks can be landed upon. Without the Jump Shoes, escape is only possible along the right side of the room. Once you make it up to the room where the Dragon Slayer sword is clearly visible, you can either return to the entrance of Lyll's area by moving to the left, or proceed on your way to the crown.
To begin the journey for Lyll's crown, you can approach the area to the far right side of Lyll's portion of the dungeon from two different directions. You can approach it from the left, or from the levels underneath as described in the walkthrough above. You will be needing the Jump Shoes in order to reach the crown. (There is one exception to this, but it requires an unbelievable amount of luck to collect two or more scrolls before you reach one particular location. More explanation will follow.)
Regardless of how you approach the room containing the Dragon Slayer sword, you will need to leap up from the right side of the room to the blocks and platforms at the bottom of the room above you. Once you make it up to this room, it is a simple matter of smashing down the blocks in your way until you reach the ladder the climbs up to the next area. You may recognize the next area as the left side of the room where you collected Xemn's Glove from. Run to the left, and smash through the blocks that bar your way in the next room, while fighting or avoiding the Mayus the roam around. To reach the next room, you can either throw on the Jump Shoes and leap up to the hole in the wall (above the chest containing bread), or you can make a series of blocks appear by jumping in the right locations and leap to the hole.
It turns out there are three different ways to proceed to the crown. All involve passing through the area on the right of the map above. If you have the Jump Shoes, and were following along with the walkthrough above, you simply need to drop down to the floor, activate the Jump Shoes and bounce up to the top of the column to your left. However, if you managed to luck out and get at least two scrolls from the Mayu's in the previous room, you can take advantage of the speed and rocket from the hole in the wall to the block ahead of you, and jump over to the column. This is the only way to reach the crown without using the Jump Shoes. The third method is described to the right.
Regardless of how you arrive, you must proceed to the left side of the room, beyond the tall column. As you walk along the top platform, you will have to smash through several blocks with your Mattock. Once you clear the column below these blocks, you have some options. You can continue to smash through the blocks and go straight for the crown, or you can drop down to the room below and stay at an Inn to refuel your life and magic. It is recommended that you visit the Inn, especially if you plan on switching up your equipment (to include the Shield or Power Knuckles for example).
Whether you drop down, or continue plowing through the blocks, the path to the crown is not easy. You can only approach it from the left. Which means you must make use of the long platform that leads to the left side of the column. The only problem is, very few blocks on that platform are real. Most are illusions. Only the two left most blocks and one other, the block that lines up with the right of the background column, can be stood upon. So either fall down to the single block from the blocks above, or jump up from the shop (which may also require smashing blocks above you in order to make the jump.) From there, you must very carefully stand on the edge of the one solid block, and jump to the left over the two illusion blocks so that you can land and proceed to the crown. If you fail, you will merely fall down to the room below and be forced to try again. If you succeed, jump up along the left side of the column and touch the chest to reveal the Crown. The boss that you fight will be determined by the order in which you collect the Crowns. See the bosses page for more information.