Two lovebirds, the first of their kind (alicorn fusions that is) united in their deep seeded relationships and in their cause to protect and to maintain their kingdoms and families for the rest of their days. From the much older yet now rejuvenated Queen Galaxia, whose fusion caused a rebirth for her component mares and a fresh new start to begin from to King Speedy Hooves himself, young and inexperienced yet collectively provides a shield and place of reassurance for the older Galaxia to be with. And so the two rule merrily together over Equestria and the rest of it's vast empire.