With the struggle against the Wonderbolts behind them, and being named King of Equestria, Indominus, Rainbow and the family are finally enjoying peace at last. Things take an interesting turn when Rainbow gives birth just like Ra had told them, but it turns out it's not just a daughter.....Indominus gets a son too. A pony/dinosaur hybrid named Viper, and a full hybrid dinosaur like his father, Indoraptor. Unfortunately, unlike their parents, Tyrannosaurus, Blue and her girls, the kids aren't quite as welcome as they think. The same ponies that looked up to the dinosaurs that saved Equestria, aren't too keen on having hybrids roaming about their world.
But fitting in is the least of their troubles. An enemy the ponies thought they had vanquished so long ago, has managed to survive and is back with a vengeance. Only this time, he intends to have all of Equestria submit to him and his authority.
The hybrids must find a way to coexist with a world that hasn't fully accepted them, and keep said world safe from one of its most deadly and powerful foes.
(Also, later on in the story there will be the appearance of a character that many of you probably know. Before anyone calls me out when that moment comes, I got permission from Somber himself to use her in my story.)