Cozy Glow's plan backfires in a way which she could not ever have seen happening. The Elder Dragon Kralkatorrik drawn in by the large consternation of the planets magic invades Equestria. It's champions locked away in Tartarus and magic stripped away All are powerless to stop him.

But a small glimmer of hope remains.

an Au of season 8 finale of MLP and Livng world season4 ep4 of GW2