This ended up being slightly cut down from what I had originally been considering, but this was something I was excited to try out.

Welcome to the next chapter of Marileth Week 2021. Today's prompt is crossover, and I decided to do one with another mobile game… Genshin Impact. Yeah, this spawned mainly because male Byleth and Aether are voiced by the same person in English. Just seemed like it would fit. I was thinking about Pokémon, but was struggling about how to make it work all that well, hence why this spawned. I'll admit I was going back and forth between making Marianne be in either Ganyu's or Ayaka's position, but some friends in the Claudeleth Discord server helped convince me that Ganyu was the overall better match for Marianne. Thanks a lot.

Not much more to say. Let's dive into this unknown world.

Disclaimers: Fire Emblem belongs to Nintendo, Intelligent Systems, Koei Techmo, etc.

"My name is Byleth. However, several of you may know me by many other names… the Traveler… the Honorary Knight… amongst others. I'm simply someone who is looking for their missing sister…"

Byleth walked around a little bit, although he was in a fairly different outfit from what he normally wore and he wasn't wielding the Sword of the Creator.

"My sister and I were traveling across many worlds, but we were stopped by this unknown god that stranded me here in this world known as Teyvat… mostly powerless. However, one day, I encountered this… fairy… looking… thing? Her name is Sothis, and she is my companion."

Sothis floated nearby Byleth, but also had a different outfit on… and was a fair bit smaller.

"We arrived in a town and aided the Archon of Anemo, Claude. He then pointed us in the direction of the Archon of Geo, Dimitri. After that and some… other… circumstances, me and Sothis found our way to the land of Inazuma and had a brief confrontation with the Archon of Electro… Shogun Edelgard. I got my butt handed to me and the new powers I had obtained from that region weren't at full power since I didn't have a good grasp on them. Following that defeat, I made my way back to the mainland to train and hone my skills…"

Byleth's sword was shown sparking with electricity and he was slashing at the air and trying to make sure that the energy didn't travel in any strange direction. He let out a small sigh at how awkward the energy flow ended up being before he set the sword away.

"You've been at this for a while. Sothis suggests we take a break and head back to Liyue to get something to eat," Sothis ended up advising.

"Yeah… that may be a good idea," Byleth nodded.

"Besides, maybe it means you get to see your friend again," Sothis gently teased.

Byleth let out a small sigh before he opened up a map and the two vanished in a flash of light.

The duo arrived in Liyue harbor not too long later and grabbed some food. As they were about to find somewhere to sit down and eat, they overheard some people talking about missing somebody and hoping for their return.

"Let Sothis guess… you wanna help?"

"Yeah," Byleth nodded as he walked over to the people in question, "Is something the matter?"

"I was told that one of the lead secretaries within the harbor, Marianne, had disappeared and wasn't returning. The other employees were struggling to deal with her workload. I had a guess where Marianne had disappeared to, so I told them I would go looking for her."

Byleth and Sothis arrived atop a mountain and saw Marianne was simply watching the setting sun.

"Oh, there you are!" Sothis called out.

Marianne turned towards the two in surprise, but smiled at them, "You two. I did not expect to meet you two here. Is it official or private affairs that brings you here?"

"We came looking for you. The people at the harbor miss you," Byleth explained.

This made the bluenette fall silent, but then turn away, "I have left the human world. It is not important for me to return. ...when I did go back from a break, I saw that my place had been taken."

"...temporarily. Because you took a break. It's not like you're being permanently replaced…" Sothis chimed in.

Marianne had a look of disbelief on her face as she took a seat on the ground. Byleth soon sat next to her and handed her a snack, "Oh… thank you, traveler."

"Not a problem," Byleth smiled.

She happily had the snack and Byleth soon sat down next to her with his own snack in hand. The two remained side by side as they enjoyed the meal.

"Marianne ended up insisting that she wouldn't return to Liyue until she had completed some kind of training. So, I assisted her with it as I trained with my Electro powers."

Marianne saw a few monsters appeared and quickly called forth her bow. She took a calming breath as she pulled back on the drawstring and fired a bow filled with Cryo energy that froze the enemies in place. Byleth generated some electric energy into his sword and swung it down at the enemies, causing them to conduct the electric energy at a quicker pace and then shatter. Marianne quickly fired off some arrows at monsters that had appeared behind them.

"I got your back, traveler," Marianne quickly told him.

"And I got yours!" Byleth responded.

The horned woman simply gave a nod in response and froze up some more enemies as quickly as she could. Byleth then dealt the finishing blow on them. The two quickly walked over to each-other and smiled at a job well done.

"We've completed the task. What do you think?" Mariane asked.

"Heh. Perhaps I'd make a good adeptus," Byleth smiled.

"I agree," Marianne nodded as she put a hand towards her heart, "You have many similar qualities to the adepti, despite sharing none of their blood."

Byleth chuckled and briefly blushed in response to the compliment.

"I continued to assist her in her training as we went through parts of Liyue occupied by the adepti and we both came out a little bit stronger. After a while, I did manage to help clear up the misunderstanding that she had with her employers and she went back to work not too long later. However, the following evening…"

Byleth and Sothis had stocked up on some supplies and were set to make the journey back to Inazuma. Just before they could start talking…

"Traveler!"

The two turned to see a smiling Marianne walking over to their side. They both turned towards her and smiled.

"Sothis thought you were going back to work…" Sothis remarked.

"I was, but I wanted to see you two off before you headed out of the harbor. I'd like to earnestly thank you for your help today, traveler. If it weren't for your help, I wouldn't know where I would be right now…" Marianne thanked.

"I had a fun time," Byleth smiled.

Marianne giggled a little bit in response, "To think… I'd find a human friend outside of my work place. It makes me happier than I could've imagined. I'd like to repay you when I'm done with the work at hand. Maybe I could… accompany you on one of your travels?"

"Wouldn't you be busy?" Sothis asked.

"I'd be happy to have you," Byleth informed.

"Alright. I'll draw up a contract for future reference. Just drop by when you can," Marianne smiled.

"It was about a week and a half before I could see Marianne again. Once she was freed up, I decided to take her with me on a trip back over to Mondstat so that she could experience the town."

Marianne gave a soft 'wow' as she looked around the area, with Byleth walking over to her side. The two ended up exploring some of the sights of the windy town of freedom together and just enjoyed each-other's company as they did so. The two soon found a calming spot to watch the setting sun.

"This town is really lovely," Marianne smiled.

"I know," Byleth nodded, "I'm glad that you got to join me today."

Marianne simply smiled a bit at Byleth before giving him a gentle kiss to the cheek. Byleth blushed a little, then just smiled like a lovesick fool...

Byleth groaned a little as he sat up and looked around a bit, seeing he was back in his room in the monastery. He then saw that Marianne was nearby and looking over a collection of books that were in his room. She picked up one of them and read the cover of it in confusion, "'Tales of Teyvat, by Mina Hoinka Yoso'?"

"Good morning…" Byleth greeted as he rubbed his head.

"Oh, sorry to bother you. Claude was looking for you for a strategy meeting and I just had a hunch you were still in bed," Marianne responded, "Were you up late last night?"

"Just struggling to sleep and those helped me sleep," Byleth informed.

"Book series you like?"

"Yeah. My favorite series of books…" Byleth admitted, "I just… find something relatable about the traveling protagonist of them. And something about one of the main girls in book three really reminded me of you… not quite sure why."

Marianne just nodded a little bit in response.

"...you can read those while I go talk to Claude, if you want," Byleth offered.

"Really?"

"Yeah. Just be sure to bring them back, ok?"

"Okay, thank you," Marianne smiled, quickly giving Byleth a kiss to the cheek before heading out.

Byleth just smiled a bit, then walked out of his room…

In case it wasn't clear, this is meant to be post time-skip. Haven't done a lot of those yet. Also, yes, the name of the person who wrote the book was meant to be a nod to MiHoYo, the company behind Genshin Impact. Thought it was cute.

I'll admit that, like I said earlier, ran a bit out of time and needed to condense some of the ideas I had down a bit, but I like how this turned out. Ganyu is one of my favorite Genshin Impact characters and Marianne is one of my favorite Three Houses characters, so the idea of them as one character is a nice thing to me.

Not quite sure what my favorite part is, or what next chapter will hold, but I hope you liked this one. And I can assure you that more Genshin related stuff is coming.

Just Live More.