Cadence sat happily on her new throne in the Crystal Empire, sipping her tea. She found an odd sort of pleasure that her two aunts seats were two steps down from her on the dais, though she chose not to indulge in that too much. Suddenly finding herself with her own kingdom was unsettling enough on its own without accidentally slipping into a megalomaniacal state, just because it was tradition in the Crystal Empire that visiting monarchs be seated two steps down from the Empire's ruler. After all, they were still family.
Celestia was the first to speak up. "So, Cadence, it seems you've had an...interesting honeymoon," she offered cautiously.
"Verily!" Luna agreed. "A kingdom of your own! However did that come to pass?"
Cadence chuckled. "Accidentally," she admitted. "Shining and I came up here for our honeymoon, and I'd used my Waterbending to shape us a comfortable igloo for a wintry wonderland...only for the frozen ground to split, our igloo get swallowed up into an abyss, and this city rise up out of the ground to rest amidst the snow." She pursed her lips in a pout. "A real mood killer, I must say. And we'd just gotten comfortable when the rumbling started."
Celestia calmly lowered her cup, schooling her features to resist showing her reaction to her niece's bluntness. Luna was not so reserved, having first expectorated her tea in a burst of laughter before offering a consoling glance. "If I may ask, why didn't you inform me when this happened?" she asked, trying to guide the conversation.
"Well, considering how unusual it was, I thought I should discover the whole story before writing you," Cadence explained. "Besides, it's been decades since my last adventure, and it popped up during my honeymoon!"
Celestia sighed softly. "Of course," she replied warmly. "Continue."
"Anyway, all the ponies here seemed to be under some sort of curse," Cadence continued the tale. "Those few I was able to speak to mentioned a wicked unicorn King named Sombra, and weren't able to give me any details beyond that. So, once I noticed a distinct absence of pegasi, I told Shining to investigate the interior of the castle from the bottom up, while I made my way to the top of the tallest tower to work my way down."
"Why would you start there?" Celestia asked, confused.
"Because unicorns love towers," Cadence replied. "Twilight lives at the top of her tree, and used to live at the top of the observatory tower. Rarity lives in the mini-turret above her boutique. The dormitories in your school are on the top floor. Even Starswirl lived at the top of a tower, according to your stories. So once I knew there were no pegasi, I figured an evil unicorn King would put anything of great importance at the top of his tallest tower, where he would be most comfortable and where it would be most easily defensible against the ponies here."
"Now why didn't we think of that?" Luna complained, sending an arch look her sister's way.
Celestia rolled her eyes, blowing air through her pursed lips in frustration. "I notice that tower seems to be in need of repair," she offered.
"Well, it did contain a heart shaped crystal that held a great deal of magic, but when I approached it, the circular platform it was on glowed, sounding an alert and trapping me in crystals that blocked magic. Since I could tell it was sounding to someone dangerous, I used my Earthbending to shatter the entire top of the tower before taking the crystal to ground level. Shining met me there...as did the entire population of the Empire, who started cheering about the return of the Crystal Heart and Crystal Princess. They also started glowing, of all things." She shrugged to herself. "When I put the Heart in its present position, energy flowed between it and all the ponies, and that dome surrounding the city went up. After that, they proclaimed me the new ruler."
"Rather efficient," Luna praised as Celestia frowned. "Pray, did you learn the identity of the one who was signaled?"
"I did," Cadence replied. "One of the ponies here, a young unicorn mare named Radiant Hope, told me about Sombra once the curse on everyone's memory was broken by the lighting of the Crystal Heart. She spoke of how he was an Umbrum - a shadow pony - placed as a foal in the Empire to eventually become a sleeper agent, twisted in his desires by the fact that the energized Heart caused him agony. Thre were a few other details, but I could tell by how she spoke of him that she loved him, and was desperate to save him from the Umbrum who only wanted to use him."
"So...what did you do?" Celestia inquired.
Cadence sipped her tea with a mischievous smile. "I used my bending to trap Sombra when he breached the shield in pony form, applied high level magic suppressors to both Sombra and Radiant Hope, and then locked them in one of the castle's guest rooms." She took another sip. "I locked them in at lunch. By dinner, Sombra was ready to listen to reason with a clear mind...especially since, with his magic blocked by a crystal I bent for the purpose, the Heart's energies didn't harm him. After attending the Crystal Fair together, I sent them to Twilight and Wan Shi Tong to resolve the rest of the problems they spoke of, since it seemed to be a matter of resolving specific magic rather than an emotional or friendship problem."
Celestia pasted a warm smile on her face. "Well, Cadence, I must say your handling of this situation was quite ingenious, and you've resolved an ages old quandary with wonderful results-"
"But you're disappointed you weren't able to send Twilight in to resolve it to test her growth?" Cadence inferred sharply.
Celestia pulled back, stunned. "Now, I never said-"
"I know about the alicorn gift of visions," Cadence interrupted. "Wan Shi Tong explained it to me. You just happen to suggest honeymooning in the far frozen north as someplace quiet where we'll spend a great deal of time snuggling, with a possible chance of a minor adventure or two...but tell me to write you if anything unusual happens? You had a vision of the Empire's return and hoped to pit Twilight and her friends against Sombra as part of your 'Emotional Development' checklist, didn't you?"
Celestia glanced away. "...it's a 'Friendship Lesson' checklist..." she grumbled under her breath.
"She planned to tell Twilight she had to do it on her own, to see if she was willing to disobey the orders and fail the 'test' for the sake of saving the Empire," Luna spoke up. "She felt she had to so she could check off 'Altruism' and 'Self-Sacrifice'."
"Luna!" Celestia snapped, rounding on her sister.
"I already told you my views on the subject matter," Luna countered. "And from the sound of it, Cadence agrees with me."
"You're right about that," Cadence replied. "I didn't know about this plan before the events unfolded...but I'd have done exactly the same thing if I had."
"What?" Celestia demanded, stunned. "But-"
"You know about the world I was in," Cadence interrupted. "You know what things were like there. I also wouldn't be surprised if Wan Shi Tong or Iroh informed you of the war, and how it ended. Though I doubt they told you of the consequences of my decisions there, the consequences I've had to live with ever since."
As Celestia stared, Luna extended a wing. "Cadence, you don't need to-"
"No, I think Aunt Tia needs to hear this," Cadence interrupted. "There were several times where I decided to gamble the outcome of a major event in that war in the hopes of getting an outcome that was somehow better than acting immediately, each time choosing not to take immediate action in the hopes someone else would - or had - resolve the situation to the greatest effect. Three major decisions came back to haunt me, even to this day. The first was when I contacted the Spirits to resolve a threat to the Moon Spirit, rather than act on that threat myself. The end result was a Kraken devouring a fleet of my own people, whose only crime was following a power hungry Admiral on orders from their ruler. Another time, I let that ruler escape rather than face his son - my cousin - in battle, for fear that battle would break one or both of them. This nearly lead to the entire Earth continent being scorched to ruins.
"But the worst is with my own cousin," Cadence continued, tears pouring down her face. "She was twisted up and broken inside, and driving herself in a mad quest...and her brother stopped her. I could have acted then, to try and help and heal her...but I decided to wait until after the war was resolved, because I felt that was more important. By the time I did help her, she was being consumed by her own fire, turning her into a walking bomb that would devastate the world." She glared up into Celestia's stunned eyes. "And I discovered just how easy it would have been for me to heal her, to save her...but by that point, I had no choice but to kill her. She died in my arms, begging me to save her...and all I could do was make it painless! I will never again risk those who look to me for protection on the chance of a 'better' outcome!"
Celestia stared at her niece as Luna moved to her side, wrapping a comforting wing around her. "Cadence...I..."
Cadence sighed, struggling to bring her emotions under control. "There's a reason I hadn't talked about this before, outside when Aunt Luna came to my dreams..." She shook herself off. "But you can understand why I can't allow my subjects to be used in such a plan. And I do understand your reasoning for checking how Twilight has grown." She took a calming sip of tea.
Celestia sat back, nodding in understanding. "Perhaps I need to reevaluate my own methods," she admitted. "It seems I have missed quite a bit, if I did not see the pain you have been going through. ...I wonder what I've missed with Twilight..."
"Just get over here and hug her already," Luna snapped.
Blinking, Celestia chuckled as she walked up to her fellow alicorns. "It's good to have you back to keep me in line, sister," she teased, joining the group wing-hug.
"Then maybe you should listen to her more," Cadence teased, earning a blown raspberry from her solar aunt.