Yes, and get Edelgard to open up a bit

Before moving towards Edelgard's room, he thought of something. 'Sothis, can you make sure no one notices the sword tonight? It can be because I don't want to make any girls suspicious of me, and keep me from winning them over.' There was a brief silence. "It's amazing how you thought of that reasoning so fast." She says, waiting for him to phrase it as a wish before snapping her fingers in his head. More confident that he wouldn't complicate more things tonight, he approached Edelgard's doorway and could hear more of what she was saying. "No... Agh... Huh?! Who's there?!" The sound of hurried footsteps came calling before her door nearly burst open, the future Adrestian Empress standing there, staring at him in her nightgown. "Professor... What are you doing here?"

Given how clearly personal the issue with Rhea had been, Byleth decided to keep her secret for now. "Sorry, I was feeling restless tonight, so I got up to walk for a bit before I heard something." He lied casually. Edelgard nodded as she sighed "Oh? Perhaps I was talking in my sleep." Then her brain heard the restless part, and couldn't help but go places that Sothis would definitely approve of. "What could that possibly mean?" She muttered, alarmed and blushing before regaining her composure. "In any case, please don't scare me like that."

"Sorry." Byleth bowed a bit in apology "Bad dreams?" Edelgard blushed a bit in embarrassment at that. "Ah... So you heard me, then. Yes, it was a nightmare. I've had them since I was a child. Stupid, pointless dreams I can't control... It's terribly frustrating."

Byleth was starting to feel concerned about her. "What are they about? Anything I can help with?" The future empress shook her head, the blush fading. "No. They're just worthless dreams of the past... my childhood. A time before I had realized who I was destined to become. Talking about it won't change a thing."

Byleth was not about to let one of his students go without at least some help, so he tried one last time. "I just want you to know you can trust me with anything. It may not be any of my business, but I'm willing to lend an ear if you need it. "Edelgard sighed, a small grin appearing over her face briefly. "I had a feeling you'd say that. I suppose I could try... But only if you swear not to tell a soul." He nodded, understanding how sensitive this must be for her.

Edelgard returned the nod, visibly relaxing briefly. "I appreciate it. I dream of...my older brother, paralyzed, helpless... my older sister crying for help that never came... the youngest babbling words beyond meaning. I see my family dying slowly, waiting in the darkest depths for a glimmer of light. I once had ten siblings, eight older and two younger. Such a large family, and yet I became the heir to the throne. Do you know why? Every last one of them was crippled by disease or lost their mind or died. I was the only one left who could inherit the throne."

Byleth was astonished at how horrific that was. "That's awful. How could such a thing happen..." Edelgard wasn't done, however. "Things kept getting worse. The darkness kept getting darker. In the end, I was the only one who survived. The nightmares are a reminder...to never forget. To never allow such terrible things to happen again."

"Never again..." Byleth echoed in sympathy. What she had described had sounded like a nightmare out of hell itself. And she said these were memories from her childhood!? Edelgard's shoulders drooped as she continued. "Even now, I'm the only one who can carry the weight of the Adrestian Empire. The future of the Empire...of everything...depends on me." She finished, before pausing as she realized something. "Hm... I shared more than I intended to. I suppose there's something in the air tonight. I've never told anyone about my past before. Please... forget I said anything. Sleep well, my teacher."

Byleth nodded. "Sleep well, Edelgard. And, thank you for trusting me with that." He said before walking away, head swimming with thoughts as he returned to his room. "That was... a lot." Sothis replied as Byleth closed the door to begin changing. It had been shocking enough that it had kept her from appreciating how sexy Edelgard had looked in her nightgown.

"Yeah..." Byleth muttered, getting undressed for bed, putting the Sword of the creator under his bed next to the lamp. "Still, not much we can do about it tonight." He pondered, before Sothis raised a finger as she was pensive. "There actually might be." She began. "It is possible for me to make a dreamscape where she feels at ease, as long as it's related to sex. She definitely opened up to you tonight. Why not make one for her tonight so you can keep the nightmares away and get to know her a bit?"