Year 15, Sister's Reign
Luna and Obitus stood leaning against each other on the balcony outside the throne room, their tails entwined together. "A thousand years. I still struggle with it, my love. Celestia should have wakened me a long time ago; if only for her own sanity."
"She found a way to deal with it. She knew how heartbroken you were, and I guess she felt that it was best to wait until I could wake you."
"Mmmm. I am truly grateful, but I still can't help feeling guilty. I owe her." They snuggled closer. "Someday I will repay her. And until then, the least I can do is take over with you and let her get some rest." They parted and turned to enter the throne room.
"Are you sure you're ready for this, my love?" Luna asked. "A lot has changed since you went to sleep."
"Yes, I believe I am. With you beside me, there is nothing I can't do." Luna smiled and kissed him.
"I'm glad. Okay, wait here for us to introduce you." Luna stepped through the curtain separating the throne room from the balcony, and took her place on the throne beside her sister.
Celestia rang a small bell, and the vast room full of ponies quieted instantly. "Citizens of Equestria, greetings and welcome! We have an important announcement to make tonight. As you know, my sister has fully recovered from her confinement on the Moon and has taken her place beside me as a Princess of Equestria. For the first time in a thousand years I can pass on the burden of leadership, and together you will forge a future as bright as the full Moon!" The crowd burst into cheering, love for Luna clear on their faces.
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Odd, Obitus thought. Celestia wasn't using the proper level of volume to address a group of subjects. Perhaps the curtains were thicker than they seemed, and were absorbing more sound? That must be it.
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"But no ruler should have to be alone as I was. Fifteen years ago, Luna awakened her Prince, Obitus, from his slumber in the mountains to the west." The crowd murmured, confused looks passing back and forth. "Very few of you know this as little more than a rumor, Obitus has not yet been seen in public. But tonight is his coming out, and tomorrow I will begin passing your leadership to him. He is wise and has a deep love for ponykind. He has been working invisibly for centuries, guiding souls back to this plane for rebirth. Equestrians, I give you Prince Obitus!"
On cue, Obitus teleported into existence on the dais in front of Luna and Celestia. He reared back onto his hind legs, black fire mane flaring and massive wings spread wide.
"BEHOLD CITIZENS OF EQUESTRIA! I AM OBITUS, PRINCE OF DEATH AND REINCARNATION!"
Luna and Celestia looked at each other and facehooved in unison.