Items: Blue Urn, Shortcake, Umbrella Box
In the deepest portion of Spinach Caverns, you'll find Tumultuous Cave. At the entrance, there's an oddly-shaped statue whose form you should recognize by now. He wants you to satisfy certain criteria before he'll allow you to proceed. He asks that you bring someone to entertain him before he'll let you pass. Doc can give you an Urn that captures monster energy. You'll need to get that item from Doc and use it to capture an interesting enemy if you want to proceed through this area. Go ahead and leave the cave, then head to Doc's Lab.
When you arrive, he's happy to see you. It turns out you've arrived just in time to help him test his device. As you watch, he'll use it on Poco. The unique monster energy will be sucked into the urn. Doc explains that you can smash open the urn in battle after sucking up a monster's energy and that monster will come out to help you for a short time. He gives you the BLUE URN to take with you. With essence de Poco in your urn, head back to Tumultuous Cave and use the item in front of the guardian statue. It will be entertained by Poco's mad dance moves and will let you into the dungeon now.
The dungeon beyond the statue starts with a staircase that leads down through a door into the next area. Once the familiar iron door falls shut behind you, break the pots to the left and right, then proceed forward. As you come around the bend, there will be some flying bat enemies. Attack them with targeted attacks to remove them. At the end of the hallway, there's a rock you can drill, and also a mound where you can recharge your drill. Use a charged drill to break through the rock and climb up the stairs beyond, which double back on themselves and lead to an archway that crosses over the stairs you just climbed. Note that as you move through this area, there are holes in the floor through which spiked tips rise and fall. Continue past those and also break through a solid chunk of rock. If you have your ribbon powered up, wear it while you drill through the rock so that the spikes don't hurt you.
Beyond that boulder, you'll come to the edge of a drop-off. There are enemies below, the poison-spewing flowers. Make sure you're wearing a high-level nightcap or the gas mask, then jump down and take care of the vicious plant life. Climb the slope and at the top, you can drill through a weak wall that should be directly ahead of you. That will reveal a path you can follow to another weak spot. Drill it and, as it crumbles, turn around and run back down the hall while a boulder rolls after you. Step aside as you emerge from the tunnel and it will roll past you, then come to a crashing halt in the area below where you killed the plants. Now you can head back up the passage to open a treasure chest that was hidden there. It contains SHORTCAKE.
Head back down the path and from there, take a left turn. As you head through here, there are stalagmites you can destroy and some Phantoms will roll down in giant balls of armor. Destroy the armor with drill attacks, then take out the Phantoms themselves before continuing up the path. There are some vases you can break up here, and to the left there're some boulders you can drill to continue into the next little area. There, destroy four more vases and finally you can pass through the door that waits nearby.
In the next room, you'll find a large body of water. There are also some vases nearby. Destroy those, then equip the goggles or nightcap if you haven't already. There are some of the large eel enemies swimming through this area, so you're going to get wet in the process of defeating them. Make sure that you don't miss any. There are a few water-based enemies in the area and two of them are eels. You should also take some time to head onto the stone ledge where there are some pots to break open. One contains a Phantom in disguise, so be ready for that.
When you've cleared the area of available pots and enemies, head over to the beige-color ledge resting just above the water on the side of the room that was to your right as you entered. Step onto it and you'll hear a tone. In a moment, another platform will appear. This process continues as you step on each one and move forward, though you need to be ready for slight pauses that occur between the sound of a tone and the moment the next ledge appears. As you follow them, the platforms will wrap around to a high raised ledge where you can pull a lever. Do so and a door will lift near where you broke the pots and the Phantom was hiding. Head down there and through the archway, into the next room.
From there, switch your headgear to the ribbon so that some spike traps ahead won't harm you if you make a miscalculation while leaping. You'll find one set on the edge of a precipice. Wait until it recedes. Now take a running jump out and over to the boulder beyond. Drop on its far side and onto a platform that restores your life meter. Now you can turn and drill the boulder. From the ledge you're on now, look out to the side and you'll see more ledges with stands resting on them. Jump out to the nearest one and use your Shock Parts on your drill so that you can set the stand to life. Now climb down a ladder to the area below.
There's a bin here you can break open for some Junk. There's also a weak wall. Switch to your high-level nightcap or the gas mask and drill through the wall to find some poisonous flowers beyond. Defeat them and drop down nearby to break open some pots. You're now in a rather busy area with its fair share of enemies. The nearest is a Phantom on the line above you. He's manning a cannon. Jump up and take out cannon and Phantom with charged drill attacks, then make sure that the stand on that ledge is fed electricity from your drill.
Now drop down to the lowest portion of the room and head left past a deactivated stand with a plant nearby. Ignore them for now; you'll be back in a moment. Turn left along the passage from there and jump up onto a ledge, where you can destroy another plant and also break through a weak wall. It just leads back to the base of the ladder you descended a moment ago. Continue along the main passage and you'll find some bat enemies, as well as another of the stands you need to activate. Swipe at it with your drill, and look behind it for a weak wall you can drill for coins. You're not done, though. Drill it three more times to reveal a passage into an area with some poisonous flowers you can destroy. Take care of them before you turn back and head to the plant and stand you ignored before. Go ahead and tend to those now.
That should be the final stand you need to activate. Some Phantom monsters will drop down in front of the door. Take care of them with short drill attacks and then proceed through.
You're now standing on a ledge above a room that stretches out ahead of you toward a bit of soil where you can recharge your drill if desired. Go there first and you'll see two purple vases near a weak wall. Smash the vases, then the wall to reveal an iron grating you can't pass through just yet. Turn around and start back toward the entrance of the room, but this time start out across a precipice that extends to what should now be your right. You'll notice there's an enemy hovering in the air above it. Jump up and use a targeted attack on the enemy, then springboard from it up to the ledge. A switch waits there, which you should pull. That will open the grate you revealed a moment ago. The enemies will run through and await your arrival at the mound of dirt. Break open the nearby bin where you are for some Junk, then head down to the mound and use charged drill attacks on the Phantoms (note that you should also drop down along the ledge to the right of the mound of dirt, where you can find three pots you need to break).
With them gone, go ahead through the archway and into the next area. There are six vases on your left here and two on your right, so break those straightaway. There's also a bin with some junk, so break it too. Here, the trail winds downward while winged Phantoms fly above. Make sure that you kill them as you descend so that your ranking for the dungeon doesn't falter. Don't be shy about breaking more vases you find, either. There are also some Phantom enemies to tend to on the ground as you descend.
When you reach the bottom, there will be some Phantoms manning cannons. Dodge the cannonballs and use charged attacks to disable the cannons, then follow that up with some charged drills to remove Phantom armor. Beyond them, you'll find the last bit of debris you can break, and a door into the next room. It's the treasure room. Grab the UMBRELLA BOX from the altar and consider the level complete. Now head back to Monster Village. Give the umbrella box to Chucky. He'll be grateful and, as expected, more Dark Mist will evaporate from the world map, this time just to the right of Tumultuous Cave. It's time to head to the next dungeon challenge: Shadow Grotto.