Okay, first of all. This is a crossover with literally almost everything. Now your real intro.

The world of Equus is in the gates of a New Age of Magic, old evils are awakening as also new powers are being discovered with new rules being written over the old ones. At the same time the new technologies are bringing to the world all kind of new inventions changing forever the life as we know it in what the ponies call an Industrial Revolution.

With all those changes taking place at the same time, Princess Celestia thinks that is time to retake an old project of hers, an organization dedicated strictly to protect innocents. Now The Royal and Night Guards along with new departments of police, intelligence, research and defense, will be coordinated under one organization: Welcome to a new era.
Welcome to Lightspeed

(I have literally no idea of what I'm doing. Characters added as the story progress. Set in the same universe as The Doom Patrol and Mare-Do-Well Strikes! but it's not necessary to read those to understand this, they are separate stories.)