Winnie the Pooh: Nightmare on Bald Mountain

Last time on the Pooh's Adventures Reboot, the Horned King, master of the Villains Vale Alliance, found the Black Cauldron and used its evil powers to free Chernabog from Bald Mountain and awaken his Army of the Dead and their 12 demon lords. Although both he and the cauldron's evil powers were both stopped, the darkness still thrives in their true homeworld, The End of Worlds, and it is here where Pooh and his friends must go in order to stop the threat of darkness forever.

Nightmare on Bald Mountain is the final episode of season 1 of the Pooh's Adventures Reboot.

Story
After sealing the keyhole at Prydain and delivering the Black Cauldron back to the Witches of Morva, the Pooh's Adventures Gang arrive at the End of the World. Goofy takes note of its composite-world nature, and Taran states that all of the worlds would be restored if they managed to defeat Chernabog, but wonders what would happen to the world itself and them by extension. Goofy says that, as a "Dark One world", it would just disappear, but assures them that, even if that did happen, they would not meet the same fate. However, Taran begins to feel regrets as he still feels he is not a true hero even after defeating the Horned King.

After fighting through several legions of Dark Ones, led by a vengeful Creeper, and the World Terminus, the Pooh Gang run into the Firebird and manage to defeat him after a lengthy battle. Afterwards, they descend into the crater of Mt. St Helens and press onwards. The group reaches the Final Rest area where a door appears like the one that was in the Awakening before the series began. Through the door, they come to the remnants of the Destiny Islands, which soon takes on a much darker appearance.

After exploring the ruined Islands for a bit, the Pooh gang soon discovers a familiar foe: the Horned King, now a ragged corpse of his former self. The Horned King soon approaches the heroes, claiming that although they managed to stop him at Prydain, it was all for naught as Chernabog, the true master of darkness itself, has already been freed and his power will soon extend to all worlds. As the Horned King speaks, he slowly starts to regenerate himself and become more and more powerful until at last, he has regained his original form. The villain goes on to explain that all worlds and hearts begin and end in darkness; thus, darkness is the true essence of a heart. But Taran won't hear anymore of this darkness nonesense, still standing by the light no matter what. The Horned King just sneers cruelly at this remark, and decides to prove that darkness is eternal by summoning his fellow 13 seekers of chaos to aid him in battle. The seekers of chaos soon unmask themselves to reveal themselves as: These Seekers of Chaos soon attack the Pooh's Adventures Gang one by one, with being the first to fall and  being the last to fall. The remaining seekers, Horned King included, retreat from our heroes before they all end up dying. Just then, the mountains of the islands split open to reveal the larger Bald Mountain. The Seekers escape into the opening with the Pooh gang in hot pursuit, but only Taran is able to get past a preset barrier. After Taran defeats the remaining Seekers, the Horned King uses the last few vestiges of his power to send his foes to a dark void, the Endless Abyss, the deepest darkness where Kingdom Hearts dwells.

There, our heroes are confronted with the masive spector of their true foe: Chernabog, Keeper of the Fires of Hell. Chernabog roars in delight at the prospect of crushing the last hope for defeating him, then summons the Army of the Dead to drag most of the heroes into a Portal of Darkness. Pooh begins to fall into the void, but the encouragement of Christopher Robin gives him the strength to fight back. As the great fight begins, Pooh uses the keyblade to attack Chernabog while the demon summons hordes of Cauldron Born and Ghostly Phantoms to stop the hero. Eventually, Chernabog is weakened for a moment, and he retreats in the crevisses of Bald Mountain to rest for a while. Taking the opportunity, Pooh enters the various portals found on Bald Mountain and rescues Taran, Eilonwy, Gurgi, Flewdder, Rabbit, Eeyore, Piglet, and Tigger one by one in that order. Along the way, the Pooh gang fights off agaisnt the various demon lords guarding the portals: The Elemental Titans, Amuk Moonrah, the Jabberwocky, and the Firebird. Eventually, all the heroes are freed and they escape Bald Mountain...just in time for Chernabog to awaken from his nap and roar viciously with killing intent at the heroes. What follows is a bloody and long battle where all the Pooh gang members use their magic and weapons to attack the great demon lord with all they got. The cauldron born and skeleton ghosts multiply in great numbers, but are all stopped completely. Eventually, Taran calls together all the heroes to lend him their weapons, combining them with Drynwyn to form the Ultima Keyblade. Using its holy power, Taran fires a massive beam of light to utterly vaporize Chernabog, ending his evil...or not.

Chernabog, now reduced in size and dying, opens the Door to Darkness, informs Taran that not even the Keyblade can seal the door, and pines for Kingdom Hearts to fill him with the power of Hell. Taran shouts that Kingdom Hearts is, in fact, light, which proves to be correct; the light of Kingdom Hearts shines out of the door and hits Chernabog full force, destroying him once and for all.

Once the great demon king is destroyed, our heroes waste no time in heading towards the door to close it forever. However, the threat is not over; several thousand Dark Ones lie in wait behind the door. The Pooh Gang attempt to close it, but even with help from all of their newly arrived friends, their efforts are futile. Just when things appear to be over, King Mickey arrives with a golden Keyblade, and the Pooh Gang manage to close the door. Before it does, Mickey assures them that there will always be a Door to Light; thus, they will be able to find their way back. And so, Taran and Mickey use their respective Keyblades to seal the Door to Darkness forever.

Soon afterwards, our heroes realize that they are now stuck in the Realm of the Shadows, leading Torque, of all people, to say "Now what?". However, no sooner does he say this when the worlds are beginning to restore themselves. Pooh only has a moment to wonder what's going to happen to them all just as the End of the World breaks apart; Pooh's allies are sent back to their respective worlds, while the Hundred Acre Wood gang, now including Taran, end up on the pathway to Queen Grimhilde's now abandoned castle, where they resolve to find Mickey...though they are unsure of where to start looking. And so ends Season 1 of the Pooh's Adventures Reboot.

However, not all is at peace. As shown after the credits sequence, we see Hades dragging himself out of the Underworld and is approaching a cloaked figure, claiming that he's but one of many roads that will be taken throughout the course of his new plan...