"You will not take her over ME!!!!" (Chrysalis)
This is happening right before my "Rebellion of the Queen" pic.
Sombra capture Princess Cadance and Shining Armor, and begin his plan to take Cadance as his bride in exchange for Shining Armor's life (of course he don't plan to keep his word).
But Chrysalis don't take it too lightly and feel herself betrayed. Sombra is struggling too inside, but he want to keep his big plans... so he is hoping, that Chrysalis will stay silent.
Chrysalis call her swarm and attack the Crystal Empire. Just in time to crash another wedding. Luckily for Cadance.