“W-why do you want to talk?” Twilight asked Celestia, her voice shaky after crying for so long.
“It’s time,” Celestia answered simply.
Twilight looked away, her eyes misting up. “That’s what Fluttershy said before she- before she-” Twilight couldn't bring out the words.
“We offer our condolences,” Luna told her gently. "We know Fluttershy was a kind soul who shall be missed.
“Listen, Twilight.” Celestia started. “You are the last element alive. You symbolize every element now.”
“And what does that mean?” Twilight asked.
Luna stepped in. “Do you know what the Elements of Harmony are?”
“Our strongest weapon in defense?” Twilight asked.
“It’s more, Twilight,” Celestia said. “But to explain that, please, take a seat. And have some tea.”
Twilight gathered some chairs, while Luna made some tea. Celestia placed the cups on the table, and poured the hot, damped, fresh tea into it.
“The Elements of Harmony,” Celestia began, “are way more powerful as we always said. It’s also a test.”
“A test?” Twilight was totally confused with that.
“See,” Luna began, “an alicorn duo can’t reign forever. Actually, they can only live for a few thousand years. And then, a new sisterhood must arise to take the throne.”
“Why can’t they rule forever? I thought alicorns were immortal!” Twilight interrupted.
“True,” Celestia answered. “But, forever, is very long. And although Alicorns don’t die, they do leave there body as spirits. They live on in the stars, guide and protect every citizens of Equestria.”
“so, Alicorns… do die?” Twilight repeated.
“Not exactly,” Luna said. “See it as… phoenixes. They come to a point in live where they have to change there old and outworked body into a new, better and higher form. Alicorns change, too.”
“So, when the rulers comes to that point, there must be an other duo, a duo who will rule over Equestria,” Celestia said. “And that’s where the Elements are for. To find the new ruler.”
“How?” Twilight wanted to know.
"See, nopony is perfect. But, they can be perfect in one facet of the diamond, the ideal ruler has to be,” Celestia explained. “And that diamond exists of five facets. Loyalty, laughter, honesty, generosity and kindness. Those five, combined, are traits that manifest in the perfect ruler.”
“So, when the end of the princesses is near, the Elements will arise. So there will be five ponies who each master one element. And the sixth element, Magic, is the student. The student will learn to master every other element,” Luna explained.
"The student is the one who’s most capable to learn every thing,” Celestia added. Luna nodded in agreement.
“So the Masters, carriers of the elements, teaches their element to the student. Once the student, bearer of the Element of Magic, fully controlled one element, the master is defeated, and…” Celestia trailed off.
“Die?” Twilight tried to keep her anxiety from leaking in to her voice. She knew what was coming.
The two princesses nodded.
“Once the Student learned all five elements, she will be ready to rise and rule over Equestria,” Celestia looked deep in Twilight's eyes. “You are the next ruler Twilight. You were the student.”
“How did you...” Twilight stopped talking as she thought. All the information was almost impossible for her to take in at once.
“Became the ruler?” Celestia finished Twilight's query. “The same as you have. I was the student once. I mastered every element, and when that happened, I became the ruler of Equestria.”
Twlight vaguely nodded, still thinking.
“And you?” Twilight's voice was just more than a whisper, but Luna heard.
“Me? I proved myself. When the Elements failed… I saved Equestria from King Sombra. The first time he rose to power, I mean.”
“Just like Cadence saved us from Chrysalis,” Twilight remembered.
“Indeed,” Celestia confessed. “She will be the second part of the sisterhood.”
“And how did it happened before you?” Twilight asked.
“The same as now. The Elements of Harmony picked six ponies. Five masters, and one student,” Celestia said. “And before that too, and before that. It has been going on like that for as long as Equestria has existed.”
Twilight looked from Celestia to Luna. For the first time, she truly realized how old they were. Both mares had dark circles under their eyes. They had grown weary of leading for so long. Twilight slowly nodded.
“So in a nutshell,” Twilight started softly, “you two will burn into ashes, and go to the stars. While me and Cadence- sorry, Cadence and I- have to rule over Equestria, because I was picked by the Elements of Harmony? And in a couple thousand years, the same fate will happens to us?”
Luna and Celestia looked at each other, and then back to Twilight. “Yes, something like that.”
“And when does all that happen?” Twilight asked.
“Tomorrow, 22:14.”
“What?” Twilight's wings fluttered nervously. “Why then?”
“You know why, Twilight," Celestia said softly. "What happened twenty years ago?”
Twilight thought for a while. Nothing particular came up in memory, but-
“Rainbow’s death,” Twilight whispered.
“And thirty years ago?” Luna asked.
Twilight thought for a little longer. “We defeated Nightmare Moon…” Twilight’s eyes opened wide. “The same date, same hour.”
“That was when you used the Elements for the first time. That was when the test began,” Celestia answered.
Twilight nodded, wiping away a tear from her eye.
*****
Twilight would never forget those last moments with her mentors. The last day they were together, as ponies, they had fun like they were a real family. And in fact, they were family. They laughed, cried, and made plans for the future. The Royal Sisters informed Twilight of her duties as the leader of Equestria. It was only facts to Twilight. All in all, the job was similar to her duties as Princess of Friendship.
But to all good things, comes an end.
At 22:13, Celestia's and Luna's strength left them. The collapsed on their thrones. Twilight and Cadence grabbed each other, and neither could help the tears.
"Hush, little ponies," Celestia told them as the stars in her mane faded. "We will never truly leave you. I am so proud of what you have become."
"As am I." Luna's cutie mark evaporated as she spoke her last words. "We will always be here to guide you, and protect you..."
Twilight and Cadence took a deep breath.
22:14
Celestia and Luna were enveloped in a blinding light. Twilight shut her eyes as their mortal bodies left Equestria. When Twilight opened her eyes again, her mentors were gone.
Twilight heaved a heavy sigh, but she managed a smile.
"Ready, Twilight?" Cadence asked softly. Twilight nodded.
"Ready."
This was the cycle, and it had completed another round. In another thousand years or so, the cycle would start again.