Acquiring the Boss Key

First up is the Death Armos room. You'll see some Poes here, so take them out. Instead of using the door at the far end, head towards it and use a Deku Flower to fly south. Once you land, put on the Stone Mask. This is super helpful for avoiding the Death Armos that patrol this area.

The usual way to deal with Death Armos is to shoot them with a Light Arrow to flip them, then get close and watch them smash their heads. But with the Stone Mask, they'll just ignore you, making it way easier to get past.

Make your way to the far end of the room and grab a statue. Place it on the switch to turn off the flames blocking a nearby chest. Inside, you'll find Small Key #4. Grab it, then exit the room using the second Deku Flower you see, heading east.

Next, you'll enter the Sky Room. Here, shoot an arrow at the Spike Mines so they collide and explode. This clears the path. Now, use the Deku Flower to fly into the northern passage. From there, fly east and enter the next room.

Get ready for the mini-boss, Gomess! You'll need those Light Arrows you acquired. This room has some Blue Bubbles, so defeat them first before proceeding.

Gomess himself is surrounded by bats. He'll attack with a scythe in a sweeping motion, which is pretty easy to side-hop around. Lock onto him and dodge his initial attack.

Now, fire a Light Arrow at Gomess. This will make the bats scatter, revealing his core. Hit the core quickly! He'll then spin his scythe like a propeller and charge at you. Side-hop this attack and fire another Light Arrow. Hit the core again. Keep repeating this pattern – dodge, shoot a Light Arrow, hit the core – and you'll defeat him in no time.

After Gomess is down, a new door will open. Head through it and you'll find the Boss Key waiting in a chest. Congratulations!