Final Friendship Battle

Final Friendship Battle is the three-part series finale of My Little Pony: Friendship is Magic.

Prior
At the start of Season 9, a humanoid goddess called Harmoneus The Creator turned Equestria into a literal hellhole and was not defeated by the second episode of the season. Equestria's major cities and landscapes had fallen and are now occupied by massive armies of demons. Up to the final finale, ponykind spent the rest of Season 9 preparing for an upcoming final battle powerful enough to destroy and/or reset Equestria. Twilight is upset about the upcoming fight and ends up in a very bad mood. All other ponies cheer her up by throwing her a party. Sunset Shimmer, who had returned to Equestria halfway into the season, puts all their memories onto a collection of DVDs, Blu-Ray discs, and VCR tapes, all of which she launches across dimensions for other universes to watch just in case ponykind fails to save the day. Using a dimension-hopping spaceship that Sunset, Lyra Heartstrings, and DJ-P0N3 build, ponykind sets a course to the location of the final battle, Crystalland, Rarity's home planet.

Part 1
An epic final battle begins to decide the fate of the universe. When the ponies arrive at Crystalland, they find it shattered of hundreds of world-destroying fights across dimensions that Rarity had with Harmoneus. Ancient tapestries show every battle ever done, complete with warriors resembling various G1, G3, and background ponies, meaning all of ponykind is meant to fight in the ultimate battle. The last few tapestries show Harmoneus creating each of Friendship is Magic's major villains but letting them act on their own, then the villains are all defeated in different ways from in their first appearances. Discord is the first to attack Harmoneus, but his magic does absolutely nothing to her. Then she uses 3/4ths of her power to erase him from existence for good, shooting down any chance of his story-breaker power ruining the series finale. After Discord's death, the various secondary ponies set traps for Harmoneus to get an advantage. All the traps strike Harmoneus, but she is completely unharmed and sends all her demons back to Crystalland.

Part 2
The Mane Six, the Background Six and various other ponies fight against Harmoneus' demons to clear a path for Twilight to reach Harmoneus herself. Twilight tries to talk down Harmoneus with a speech on the power of friendship, only for Harmoneus to effortlessly subdue her mid-sentence, then absorb Twilight's entire body and soul. Starlight Glimmer engages Harmoneus shortly afterwards, but Harmoneus effortlessly defeats her too. Beaten to an inch of her life, Starlight uses up the rest of her energy in a powerful laser beam in an attempt to kill Harmoneus, but Harmoneus is still unfazed and kicks Starlight into an exploding airship. With the defeat of Twilight, Rarity gets angry enough to reach her ultimate power, starting the real final battle with Harmoneus in space.

Rarity eventually destroys Harmoneus' body by slicing her to pieces with a giant crystal blade, then extracts Twilight from the sliced-up body. However, Harmoneus' soul survives, returns to Planet Equus, transforms into a much larger and more grotesque form with plenty of heads, eyes, and arms, and fires a Death Star-level laser at the planet. To stop the laser, Spike grows to the same size as Harmoneus and fires an equally powerful fire blast at the laser, cancelling out the laser but exhausting his fire breath.

"Friendship is Magic" (Part 3)
Spike and Harmoneus engage in a fistfight before Harmoneus zaps Spike with a laser that de-ages him back to his egg form. Enraged at Spike's defeat, Rarity stabs Harmoneus through the heart with the same sword that had destroyed Harmoneus' body, but this doesn't faze Harmoneus in the slightest. Meanwhile, ponykind has cleared Crystalland of demons. Giving one more speech on the unbeatable magic of friendship, Twilight rallies all background and secondary ponies to use really powerful fandom-given forms, mecha, and powers to destroy Harmoneus' many heads, eyes, and arms. With 95% of her final form destroyed, Harmoneus eats one more finishing move: A final Falcon Punch from Rarity that is powered by all the friendship of ponykind and also launches Harmoneus straight into the sun, completely destroying the goddess. Epilogue scenes for various ponies are shown over the final credits, and in a post-credits scene, ponykind gets a picture of one more group shot. Pinkie Pie closes out the show by declaring "Good show! Jolly good show!"

Part 1
Europe - The Final Countdown (plays again during the final finishing move in Part 3)

Part 2
Metal Gear Rising: Revengenace - It Has To Be This Way

Part 3
The Wonderful 101 - Jergingha Planet Destruction Form

Bomberman 64 - Credits