MLP: Royal Pains (The Next Generation)

As all the children of the Mane Six and friends have grown up, they must take their places in society. King Sombra redeemed himself, and happily married Princess Twilight Sparkle, introducing Prince Orion Solstice to the world. When Orion and Princess Flurry Heart are both of age, the two must come to an agreement: who will rule the Crystal Empire? Will it be the current Empress's only daughter, or will it be the only remaining relative of the Unicorn King?
The new royals must find their answer with the help of their friends and family and must defeat evils that resurface with their growing power.