Yeah Equestians like to come in, and go with a bang XD
But I think here they have a good reason, as it seems Chrysalis kidnapped Shinning Armor, and possibly Cadence, as I think she would lead the mission to reclaim her husband. I also see from the looks of it, that Changelings are Drows here, guessing from their queen's choice of clothing, which makes sense seeing how they seem to be a dark reflection of Equestrians. But I also see that all of the changeling army aparently have the same mind-controlled eyes as Shinning Armor, so this may suggest that they are also mentaly enlsaved their dark queen. This would be a particulary dark twist, and it would make them the biggest victims of this conflict.
Queen Chrysalis-"Naive fools! I am not alone! I am never alone! Let me show you the true power of the changelings! Our bond that is greater than friendship! Our bond that transcends life and death!" *horn glows as crown does as well and a legion of spirits of dead changelings marches to her side. She points at the enemy* "THEY ARE THREATENING THE FUTURE OF YOUR CHILDREN AND THE ONE OF YOUR CHILDREN'S CHILDREN! DESTROY THEM!"