From outside Level 8, head down two screens and enter the portal to return to the Temple Remains. Exit the room with the portal and use a Gale Seed to warp to Horon Village. There are two remaining pieces of heart left to acquire and they are two of the most annoying ones to get. One can be acquired by bumping into Maple, in which she sometimes will randomly drop a Piece of Heart. If you have the Maple Ring, you should wear it, as it will cause Maple to appear at select screens each time Link has defeated 15 enemies.
The final, and perhaps most annoying of all the heart pieces in the game is found within a Gasha Nut. Link will need to plant a Gasha Seed and defeat enough enemies so that it blossoms into a Gasha Nut. The more enemies that Link defeats, the more rare the item that is within the Gasha Nut. Furthermore, if Link wears the Gasha Ring, it will also increase the chance of acquiring a rare item. From my experience, the rarest of items are often times other Magical Rings and not the Piece of Heart. In any case, just keep planting and trying to find one. I recommend saving your game before slashing a Gasha Nut. If it isn’t the Piece of Heart, reset your game and try again. This way you won’t have to endlessly plant Gasha Seeds.
Both the Maple heart piece and the Gasha Seed heart piece could have been acquired much earlier in the game, but often times they aren’t acquired until this very late stage, because of their rarity.
After warping to Horon Village, head up one, right one, and up two screens into the Maku Tree’s area, who has returned to full power at long last thanks to Link’s efforts. After speaking with the Maku Tree, he will give Link the Maku Seed, the important final item needed to enter Onox’s Castle. After speaking with the Maku Tree, Onox will appear in his castle and challenge Link to face him.
Exit the Maku Tree’s area down one screen, then use a Gale Seed to warp to North Horon. Head down one, left one, and up one screen. Continue left one, cross the bridge, and up two screens from here, then enter through the hollowed log on the left to the Temple Remains area. Head up one, left one, and up one more screen to reach Onox’s Castle.
With the power of the Maku Seed and the eight Essences of Nature, Link can now break through the dark magic that had prevented him from entering this area before. Once the magic has dispelled, the old woman who visited Link earlier in front of the Ancient Ruins will appear and reveal herself to be two Gerudo witches, Koume and Kotake, collectively known as Twinrova. They will inform Link that the Flame of Destruction is nearly lit, and despite his efforts, the “Evil King” would still return.
After Twinrova fly off, and some brief words of encouragement from the Maku Tree, head up two screens and enter Onox’s Castle.
The rooms on the right and left contain Fairies, though if Link enters all the way into the room a door will close and tiles will lift from the floor and fly towards him. You could try and catch the Fairies with the Magical Boomerang and not go all the way past the doorway to avoid this. Each room Link progresses “up” will have these Fairy rooms on each side, but entering and exiting one will send him back to the first room of the castle.
From the first room of the castle, head up one screen and defeat all the Wizzrobes that spawn. Continue up another screen to face an array of Red Darknuts, as well as Floormasters that will try and grab Link. When all enemies are defeated, continue up another screen where Link must face the mini-boss from Level 2, Facade. Defeat him the same way as before by throwing bombs at its face and and continue up two screens, where Link will reach the chamber in which Din is being held captive.
The crystal which encases Din will separate into four sections and disappear, just before a huge spiked ball will come crashing towards Link. Onox will then walk down and have a few words for Link before the final battle begins.
** Final Boss: Onox **
Onox will swing his ball n’ chain weapon over his head and often hurl it at Link. His other attacks include causing boulders to fall from the ceiling and shooting whirlwinds at Link. Onox can only be damaged by performing a Spin Attack on him. Continue avoiding Onox’s attacks and damaging him until he brings the captive Din into the fight, attempting to shield himself with her. Using the Rod of Seasons, knock her out of the way and continue slashing away at Onox. Once he is defeated, walk over to Din and she will disappear. Holes will begin appearing in the floor. Head down one of them to face Onox’s second and true form.
** Final Boss: Onox the Dark Dragon **
The second phase of the battle is against a huge “dark dragon”, the true form of General Onox, who Link learns was summoned from the Dark Realm by Twinrova. During this battle, Onox will attack Link by either trying to squash him with his hands, spitting out blue flames at him, spitting out red orbs from the outside of the screen to the inside and back outside, or swiping his hand from one side of the floor to the next. Jump over the blue flames to avoid them. As for the red orbs, just move out of their repeating path to avoid contact. If Onox starts to swipe his hand from one side to the next, quickly head to the opposite side as his hand will not reach the full distance of the screen. When Onox tries to squash Link, he must jump on top of his hand. When Onox brings his hand back near his head, jump from it and slash the crystal on his head with Link’s sword as he falls. Link can also charge a Spin Attack for added damage using this same method. After enough damage, the dark dragon will fall and Din will be saved.
When Din is lowered, walk over to her and the crystal will shatter. She will thank Link for all he has done and various places throughout Holodrum will be shown returning to their normal seasonal order. After deeming Link a Hero, Din will briefly inform him of another quest that will call him to another land very soon. Twinrova will have a final word before the credits as they watch on through the now lit Flame of Destruction…
After the credits, you will be given the Secret to Labrynna. Copy this down as it allows you to continue Link’s quest in the Oracle of Ages. You will also be given the option to save your game. Starting this file again will allow Link to continue exploring Holodrum after Onox’s defeat. Many characters throughout the land will offer more “secrets” for Link to use in his quest throughout Labrynna, as well as the ever-important Ring Secret which can be obtained from the Ring Shop, allowing Link to carry-over all of the rings he obtained in Holodrum.