When everypony in Equestria began to celebrate the 2nd anniversary of the defeat of the Legion of Doom, these strange, horrendous creatures invade Canterlot and take away the most important beings in Equestria, hence, the Old Six, the Mane Six and the Young Six.
This leaves Spike with a very traumatized, sorrowful feeling, but intel of their whereabouts is revealed when a strange being from another world, who's had experience with this peculiar threat, summons him and the Equestrian Leaders to the world where the Afterlife itself, is open to them. Spike vows to not return from the Shadowlands until he brings those who were taken, back home. Along the way as he learns about the afterlives that lie within, he meets these strange dragon kids who have very peculiar traits that resemble the Mane Six in the purest forms of what they do for others.
Follow Spike and his friends as they help these new dragons fight back against the coming darkness of the afterlife.
Disclaimer: I own nothing of the franchise and own nothing of Warcraft.
Takes Place After 'The Ending of the End', but 'The Final Problem' never happens.