It's has been some time since Lord Garmadon escape the Underworld and Equestria has nothing but peace.

Peace is boring, there's no one to save, there's nothing to do. That wasn't until Lloyd Garmadon, son of Lord Garmadon, started to cause trouble by opening the serpentine tombs. The the ninja one have their hooves full with this.

That is if they can stop fussing over who is the Destin Light Ninja and unlock their true potential.