After Queens Celestia and Luna lost their connections to the Elements of Harmony, they were passed on to Twilight Sparkle and her five friends, who not only wielded but embodied their power. They used their power to defeat dangerous foes as well as spread the magic of friendship throughout Equestria and beyond.  
But what ponies didn’t know was that without the Elements, the Queens’ power was slowly declining. Sure, they could still raise the Sun and Moon with ease, but there was no longer any guarantee they could take on a villain head-to-head. Some ponies gossiped that they were lazy and useless, pawning their problems off on Princess Twilight and the Ambassadors of Friendship. But even with maximum effort, they just couldn’t. And the problem was only getting worse.  
As time went on, the Queens produced heirs of their own. Celestia had a son thanks to the generous sperm donation of her lost lover, and Luna sired a daughter and adopted a stepson from her political marriage with the redeemed Queen Chrysalis. With their own children being alicorns at birth, along with Empress Cadence’s young daughter, the Royal Sisters had faith that they could leave Equestria in good hooves.  
After a couple hundred years, Celestia and Luna’s power was only dwindling. Eventually, even raising the Sun and Moon left them fatigued. They were forced to come to the realization that they were slowly dying, like stars losing their energy. The only thing they could do that wouldn’t leave Equestria in shambles was to prepare their children to take the throne, before departing from the world as their souls became one with their celestial bodies. That way, they could at least continue to control the Sun and Moon, even if they were no longer technically alive. Their children were ready, right?  
With time running out, they left that question up to the universe to answer. After a thorough preparation process, a grand and public ceremony was held. Celestia and Luna announced their stepping down from the throne, simultaneously passing the crown onto their children as Equestria’s new rulers. And then the deed was done. Ponies were shocked at the sudden change. Their beloved rulers, who had protected them for millennia, were gone. They didn’t know what to make of these new rulers. Even the rulers themselves had a lot to get accustomed to, handling their responsibilities with varying degrees of success.
 
Prince Velvet Shade definitely handled the new change the worst out of all the new rulers. Already emotionally unstable from his ultimate failure to reunite with his father, not to mention the immortal curse of outliving everypony he knew and loved, he was not prepared to rule a nation. Ridden with anxiety, he could hardly even rule himself. Because of his unfit state, Velvet turned down the title of King and mostly serves as a figurehead rather than an actual ruler. In particularly bad bouts of anxiety, he locks himself in his room and obsessively looks over documents and videos of his lost father, still in denial that he really failed. With how bad his mental state has gotten, and how useless he is as a ruler, Velvet often catches himself wondering if any of this is really worth it anymore…
 
Empress Flurry Heart, while not in charge of a whole country, has her own challenges and hardships that come with being a ruler. Wise from experience, Flurry rules over the Crystal Empire alone, doing her best to create love and light when she cannot have it herself. She lost everything—her parents, her honorary little brother, her husband, and even her own children. Despite being the new Empress of Love, she has vowed never to love again. Sure, she loves her subjects and would do anything for them, but it isn’t the same. Under a collected and wise front lies a broken heart…
 
Queen Firefly has definitely handled the change in leadership the best out of the three. With Velvet unfit to rule, Firefly gladly accepted the title of Queen. Despite shirking responsibility in her youth, she has taken on the demands of Equestrian leadership quite well. When she’s not busy ruling, Firefly can be found messing around with her old friend Bedlam, or flirting with her royal assistants for fun. Yet, this flirtatious attitude is only playful and meaningless, not filled with hidden desire like it was with certain lovers from long ago. Firefly may continue to enjoy the occasional sexual partner, but none of them have been romantic. She keeps mementoes of her children and grandchildren, and enjoys watching her distant descendants grow up and carry on their legacies. Yet, historians who look back in her records are perplexed to find that the dam/sire (?) of her children is completely unknown. Welp, she was always an adventurous one.  
Firefly also dearly misses her own parents; with Queen Luna’s decoronation, Philia mysteriously disappeared and soon after went Queen Chrysalis. She often wonders where they went and what became of them. She isn’t yet aware that her once beloved brother is planning an attack on the crown…