Mask of Mists

Missable.

The 10 Stone Masks are required for the Mask of Mists ending but even so, these are all easily missable (which in turn, of course, makes that ending itself missable). 5 of the Masks are found within Dungeons 2-6, then the remaining 5 are located in the open world/inside buildings. Their locations are as follows:

• Mask 1: In the first house you enter (with the kitchen and hidden library room), head upstairs and break the boards blocking the room at the top of the stairs (if you don't have a sword yet, there's one in the room down the hallway on the left). Break the crates to reveal a chest. The Mask is inside the chest.
   
• Mask 2: After you replace the Lever near the gate and go through it, follow the path all the way down until you reach a broken bridge. Jump down and in a small alcove on the right will be a chest. The mask is inside the chest.
   
• Mask 3: Inside Dungeon #2 (accessed after completing the 4 Green Statuette puzzle). After draining the first room full of acid, you'll need to do the same to the next large room you come to. After you place the first valve down, you will gain access to a side room where you have to jump across some platforms to pull a lever that opens a gate on the left. Ignore the lever for now and instead, make your way all the way to the right of the room. On the wall will be a block with 3 scratch marks on it. Interact with this to open up a hidden wall, revealing the mask.
   
• Mask 4: Before you can complete the second dungeon, you'll need to exit it through a side entrance/exit so you can create another anti-rust potion. When you get outside through this side entrance/exit, there will be a set of ruins on the left. Make your way up the hill to the top of them and while on top, look to the left to see an interaction symbol on the top left of the ruins. Carefully make your way across the top and over to this spot to find the Mask.
   
• Mask 5: Inside Dungeon #3 (the Dungeon accessed via the well, just to the right of Dungeon #2). Near the beginning of the Dungeon, you'll come to a room with two Crystals in the center and a handful of doors around the room. On the left side of the room will be a gate that opens up after you break 2 Crystals and to the right of that will be a gate that opens up after you break 3 Crystals. Break the 2 Crystals so you can enter the first gate and when you go inside, look to the right and you'll see the Mask stuck behind some gates. On the ground just in front of it will be a button. Break the Crystal in this first room so the gate that requires 3 Crystals opens up. Head inside and there will be two "dice" blocks. Pick one up and bring it back to that button and place it on it. The gate on the far side of the Mask will open up. Head back to the room that required the 3 Crystals and grab the Mask.
   
• Mask 6: Inside Dungeon #4 (the one you need to drain the acid in front of before you can enter it). After you pass the first room where you had to raise the platform up to cross through, you'll come to a much larger room with 3 platforms that you need to raise. Before you do so, take one of the "dice" blocks and head to the platform on the far side of the room and look left to see a 4th platform down a small hallway. Stand on the platform and just past it will be a button. Toss the block onto the button to raise it up. Go down the short hallway and there will be a lever in front of you and the Mask to the right (behind some gates). Pull the lever and the far gate will raise. Make your way back to the main area and raise all the platforms required to pass through the room. When you jump across them, turn right to find the open gate and Mask.
   
• Mask 7: Requires the Magical Sword. After you complete the puzzle with the 4 shields/crests, go through the newly opened door and the path will split left and right. Take the path left and there will be some ghost vines on the left. Break the vines with the Magical Sword and the Mask will be in plain view just behind them.
   
• Mask 8: Just past Mask #7 will be a long trail with some pink poisonous gas. Make your way through this (use dash with if you need to) and when you reach the other side, there will be a set of ruins on the right. Go inside the ruins (mind the enemies) and break the crates. Just behind these, inside the wall, will be the Mask.
   
• Mask 9: Inside Dungeon #5 (the one accessed after climbing the beanstalk). As you progress through the Dungeon, you'll eventually come to a room with 12 platforms that you can jump across to get to the other side of the room. Stick to the far right side and jump to the 3rd platform. Look off to the right to see a hallway down below. Make your way through the hallway and when you reach the room at the end, the Mask will be inside. Be sure to use your dash () to get through the poisonous gas if you need to, especially if you didn’t drink any Breathing Potions.
   
• Mask 10: Inside Dungeon #6 (accessed through the Graveyard). Make your way through the Dungeon and you’ll be introduced to hidden walls that appear when you get close to them. Eventually, those walls will turn into floors that you can walk on. After the first room with these floors (you'll cross over 3 platforms), you'll come to a much larger room. The platforms start next to the stairs on the far left. Go forward on the disappearing/hidden floor until you can see an opening on the left. You need to play a little game of trust and jump across into this opening and you’ll land on another hidden floor. Make your way to the end of this hallway to find the final Mask.

Once you have all 10 Masks, you'll need to backtrack quite a bit to actually "turn" them in. Make your way back to the first house you entered when you started the game and go through the gate to the left of it (the one you had to replace the lever on). Follow the trail all the way until you reach the broken bridge. Make your way across the log bridge and head to the right. Because it's now raining, you can cross over the red/orange flowers. Do so and you’ll come to an area with 10 busts that are missing faces. Interact with each of them to place a mask on each one. When you do, a pedestal will appear in the center with a Gilded Mushroom on it.

The trophy will unlock once it appears but make absolutely sure you pick up this Mushroom, because it's required for the second ending (Mask of Mists). If you go through the final portal without picking it up, you'll need to start a new playthrough to get this trophy. If you're having any trouble or need assistance in finding and/or completing the dungeons, please see Mask of Mists for complete video walkthrough.