With all eight Essences of Nature, return to the Maku Tree in Horon Village. He will use the Essences to create a path to Onox's Castle, which rises from the ground in the northern part of Holodrum. The castle itself is a final dungeon, filled with the toughest enemies and most complex puzzles in the game. You'll need to use all your items and abilities to navigate its treacherous halls. There are no new items to find here, but you'll need to collect the Boss Key to reach Onox. stock up on Potions, Bombs, and Seeds before entering. The castle is a gauntlet of challenges designed to test your mastery of the game.
