Completing Merlin's storyline in Disney Dreamlight Valley unlocks the ultimate solution to the valley's most stubborn obstacle. Reaching Level 10 Friendship with the wise wizard opens up "The Final Trial," a quest designed to permanently upgrade your Royal Watering Can. By finishing this mission, you can finally clear out the large mushroom clusters blocking critical paths like the stone bridge in the Glade of Trust.

Prerequisites and Preparing Purified Night Shards

Before initiating this quest, players must reach friendship level 10 with Merlin and unlock WALL-E through his initial realm quests. Once activated, Merlin tasks you with crafting five Purified Night Shards at any crafting station using Dream Shards and Night Shards. These items serve as the foundation for the magic potion required later in the experiment.

After crafting the shards, visit WALL-E so he can crush them into fine magical powder. Take the crushed material directly back to Merlin to receive a special seed and further instructions. He will present a list of mystical ingredients necessary to construct the ultimate upgrading ointment.

Gathering the Mystical Quest Ingredients

The enchantment recipe calls for three key components: 15 Mushrooms, Falling Water, and an Ice Heart. Mushrooms are easily gathered along the ground in the Glade of Trust or harvested from smaller mushroom patches. Collecting enough mushrooms beforehand saves significant time during this stage of the quest.

To locate the Falling Water, head to the southernmost edge of the river flowing through the Glade of Trust. Look for a sparkling interaction spot right near the waterfall edge where the stream runs off the map. Interacting with these sparkles allows you to collect the bottle of Falling Water instantly.

The Ice Heart requires a quick gardening effort using the Ice Tear Seed provided by Merlin. Dig a hole in any biome, plant the seed, and water it thoroughly. The plant grows within moments, allowing you to harvest the Ice Heart directly from the ground.

Crafting the Ointment and Upgrading the Watering Can

With all three ingredients gathered, head over to any crafting workbench across the valley. Open the Potion & Enchantment section to craft the Royal Watering Can Upgrading Ointment. Bring the finished ointment directly to Merlin so he can apply the enchantment to your tool.

Merlin will grant your Royal Watering Can its final upgrade, allowing it to dissolve massive purple mushroom clusters. Walk over to the Glade of Trust and use your upgraded tool on the giant mushrooms blocking the central bridge. Removing these obstacles restores complete access to both sides of the biome.

Completing the Quest and Claiming Rewards

Return to Merlin after clearing the path to share the news of your success. The wizard expresses his pride in your magical progress and officially concludes his friendship storyline. As a final reward, you receive 880 Friendship points and Merlin's Marvelous Wizard Hat.

Fully upgrading your tool ensures seamless exploration throughout the valley without environmental barriers. You can now clear any remaining large mushroom patches in other biomes whenever you need additional resources. Mastering this quest marks an important milestone in restoring freedom to Disney Dreamlight Valley.