Speak to Dereo and tell him of your success. Tell her you found the mosaic, then return to Dereo. There's random items, but the two important ones are the Legendary Shield and Poleaxe.ДЄfter killing the boss and getting your loot, return to Gwenfin, who's at the cave entrance. With the wall open, you can loot the stuff inside.

It can be found near the center of the map by investigating a semi-submerged statue. Place both Cornetts in it to open it (if you never found the other one, take the time to explore the Old City Ruins to get it. AoE spells like Fire Wall also work well, as the boss will stand still while charmed, continually taking damage from the fire wall. While charmed, you can still attack it, you just need to do so manually. Also, the boss is very weak to charm, and can be charmed repeatedly with ease. Try to cast spells that lower his accuracy, or buff your tanks defense so that they can absorb the blows. The boss hits only one target at a time generally, but can hit very hard.

Next, focus down any small grubs, then start dealing with the main one. If you don't enemies will spawn continually throughout the fight. Once inside the boss fight, head behind it and kill the Grub Den first. Inside is a very big boss, so prepare accordingly. Investigate the statue and place the Cornett to open the giant wall. You will find the temple in the top-left of the map. Your goal is not in the Old City Ruins, where you start. It's very likely you've been here before, but if not, take the time to explore the whole region so you can get the experience points and loot. Walk inside, and you'll be in the Old City. Once in the Undercroft, head to the Old City Ruins marker, where an NPC with a torch will greet you. The thug will move, allowing you to go down (assuming you haven't come this way before). Head to Delver's Row, and go to the back. He will be pleased, but then tell you that you're far from done. Return to Dereo and show him the Cornett. Wait until the area is clear, then unlock it and grab the Cornett. Then go downstairs and you'll see a chest that will specifically say works with the key. Go into the back of his house and loot everything until you find his key. This will require a high stealth character though. Pick whichever one is appropriate for you to get the Conch. Suggest that he uses the money to fix up his villa, and then several payment options will be made available. Keep talking to Takano, and tell him you will purchase the Cornett off him. To reach the old city, you must take the lift in the top right corner. This one is found by exploring the Old City, a region accessed through The Gullet district. If you speak to Takano, you can learn that there is actually a second Cornett. It requires going to Serpent's Crown and getting a Cornett of Waves. Speak to Dereo to learn he has a job for you. Get the Cornett of Waves from Takano's Villa in Serpent's Crown When guards approach, tell them Dereo sent for you. Go right, right, then left, then look for signs of svef use. Head to the Narrows, an area within The Gullet. A messenger tells you exactly what to do for this step.

Pillars of eternity deadfire map