A/N
Got a little bit of a side story here. It's completely separate from "What Am I?" Essentially, it's my own take on what would happen if Rhea succeeded in the holy tomb. There will be two pairings (However, there won't be any romantic moments to speak of) That being F!Byleth/Edelgard and F!Byleth/Sothis. How can Byleth even be involved in this story, you might ask? Well, let's just say that Sothis is not exactly pleased with her daughter.
Rhea's POV
The culmination of my efforts is here, Rhea thought as she watched the professor striding towards the throne. She frowned, as part of her realized there would be consequences for her actions. None of it matters. She cannot stop now, and everything will be right again when her mother returns to this world. "Do you recognize this throne, professor?"
Byleth's POV
Scowling as he did recognize this throne, she said to Rhea "Yes, it belonged to a dear friend of mine. Good thing she was observant, or she wouldn't have heard Rhea say "So long, I have waited for this day…" Byleth knew she shouldn't sit on the throne. She could almost hear Sothis screaming for her to stop. But, curiosity is a powerful feeling . As such, Byleth took a seat. And then everything went white.
?'s point of view
Her greatest friend was currently laying in front of her throne in the darkness. "Byleth…" she mumbled aloud. Floating off her throne down to where Byleth lay, she cursed her long-forgotten memories. "I should've known, this is all my fault. But to think her obsession with having me back would drive her to do this?" Waving her hands all over the place as if to emphasize what "this" was. One thing she appreciated about Byleth was how even after Byleth learned that she was a goddess, (Although, she had a problem with the term since long before Byleth's birth) she didn't start bowing in some false sense of piety. Didn't treat her any differently, just said "That's great Sothis! We learned something about you." When asked why she didn't fall to her knees, she replied "I don't give two craps about that bullshit. You'll always be my friend Sothis." Giving a small laugh, she wondered if she could just stay here frozen in time. It would be much less painful. Yet even she knew that was not possible. Far be it for her to keep the Academy's favorite professor all to herself. She smiled to herself as she thought about fond moments.
Byleth's POV
This is almost comedic. I've died again? Two times was enough. When she opened her eyes, she saw Sothis floating above her. "I'm never sitting on that throne again… Sothis!" Wrapping the smaller girl in her arms, she said "I've missed you so much." Sothis sighed and said "As wonderful as it is to see you again, we are short on time." Byleth said "I thought we'd never be able to talk again?" Sothis then said "When I gifted you with my power, it made your soul almost crack in two. However, your soul received just a little bit of an edge if we're talking about percentages. There was one thing I didn't account for. That being my throne and it's magic. Oh Byleth, if we only had more time. I just wanted to apologize." Byleth then said "You're speaking in cryptic language again." Sothis huffed and said "I didn't give you all my power, if I did you would essentially be supplanted by me. Which is exactly what is happening right now. I just wanted to apologize and make a promise. I swear I will bring you back-" Byleth cut her off by saying "OK." Sothis had feared this. Byleth continued and said "While that promise is appreciated, there's three more I NEED you to promise me." Sothis raised an eyebrow but waited for Byleth to continue. "The first of course is that no matter how long I'm gone, please take care of my students. The second is that I want you to make the world a better place. With access to all your abilities, I think you can think of a few ways to make that happen. And the third is…." Taking a deep breath, Byleth said "Search my father's office. There will be a gift for you and a letter there. One last thing." Sothis paused and Byleth said with a smile as bright as the sun "I love you, Sothis. If anyone can bring me back, it will be you. Now, you can go." Byleth's answer shocked her. She wondered if Byleth had indeed been preparing for a scenario such as this. As she felt herself lose control of time she said "I love you too, my oafish boulder." The last thing she saw was Byleth's radiant smile.
Ambiguous POV
Everyone, from students to guards to the servants were engrossed in what they were seeing. A green glow had erupted from the professor. It blanketed the entire room in green light. Edelgard herself was speechless, so much so that she gave the signal for her troops to hold position. The only person who didn't look shocked into silence was Rhea, who had a bright smile on her face. Seteth then went pale "Rhea, you didn't…" he said which went unheard by everyone except for Flayn who was at his side. Being inside the tomb they obviously didn't notice the pillar of green light that started in the center of Garreg Mach and traveled into the sky. It could be seen from miles away. A scream of agony came out from Byleth, prompting Edelgard to run forward before being held back by Rhea, who gave her a look. Her eyes were now draconic slits, and her smile could put Thales' to shame in the creepy department. Hubert had by now come up and practically dragged Edelgard back.
Sothis's POV
Opening her, no Byleth's eyes she looked at everyone. Edelgard was the first to speak "My teacher, are you….. ok? " Sothis felt an unimaginable pain when she heard the words "my teacher." Not speaking for a moment, she then spoke for the first time "No, I don't think I am."
Edelgard's POV
Aside from the obvious concern that her answer gave Edelgard, Byleth's voice had changed. It seemed to echo around the room. There was power in her voice. A power that was not human. Even her presence was different, she now commanded a suffocating aura that was not too dissimilar to Rhea's. Looking at Hubert, he seemed to notice the changes as well. She gave the signal for "Arundel's" guards to help her troops retreat. This was not part of the plan.
Sothis's POV
Finally, her eyes landed on Rhea. That pain and guilt came back and she tried to prevent herself from yelling, but-
WHAT HAVE YOU DONE!