War for existence

In the country of Equestria, there was a wedding for Princess Cadence and Shining Armor, but there was also a threat against Canterlot at the same time. Shining's younger sister, Twilight, had attempted to warn them about the threat, but was excluded from the wedding and sent to the caves below Canterlot.

There, Twilight found the real Princess Cadence and helped her escape before it was too late. They got back to the throne room and successfully revealed the threat. After Queen Chrysalis explained her plan to take over Canterlot, there was a very intense rumbling and a bright flash of light when a portal in the sky opened and sent out thousands of flying high-tech ships into the skies above Canterlot.

The biggest ship fired a beam which destroyed the shield protecting the city in one shot, forcing the changelings to scatter. The ships approached the city and Lord Doom was projected in front of them. "Citizens of this universe" he said, "I am Lord Doom, and I have come to burn your universe till there is no life."

Upon hearing this, Chrysalis was more scared than she had ever been. As much as she hated helping the ponies, it was that, or sit as everything burned and all creatures were a memory, changelings included. Meanwhile, while the ponies were fighting the ships, one of them dropped a special device capable of creating portals to other universes. Twilight caught it with her magic and fired it, creating a portal to a castle filled with mushroom people. Twilight stared at it before she and her 5 friends jumped through the portal to get help.