Disclaimer: I do not own Fire Emblem: Three Houses or its characters, I only own Blythe, Celine, and the changes in the plot that I make in the war phase.

Enjoy!

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Last Time:

Byleth was about to leave, until Dimitri said, "Although, I forgot to mention that the Blue Lions have two new students."

Byleth turned to Dimitri again. Dimitri then continued, "You should know the two students pretty well. One of them is actually close by."

Dimitri then nodded towards the tree. Someone came out from behind the tree. Byleth couldn't believe his eyes.

"Surprised?" The person said with a smile on their face. "I thought you knew me better."

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Byleth was looking at his younger sister, who was to the left of Dimitri. She was wearing a silver Officers Academy uniform, which contrasted with her turquoise hair very well. She was the one who came from behind the tree. Blythe put a hand over her heart and gasped dramatically. "I'm hurt! Did you not recognize me at first?"

"No. I did. I was just surprised about seeing you in a uniform of the academy. I never thought you would be enrolled. Is Celine enrolled too?" Byleth said.

"Yeah. She's the other new student of the Blue Lions." Blythe responded. She then said, "Now don't pick the Blue Lions just because we're in there! Pick the house that you think is the right house for you to teach."

Byleth nodded. He then told both of the people in front of him, "Well, I should probably return to the audience chamber. Farewell."

He then turned around, and walked to the audience chamber.-------------------------------------------------

Byleth returned to the audience chamber. When he entered, it seemed that Lady Rhea was anticipating his arrival, because Seteth stood at her side. Manuela and Hanneman were also in the chamber. At Byleth's arrival, Lady Rhea said, "Welcome back, Professor."

Manuela and Hanneman turned to see their fellow colleague coming up. Byleth stopped in the middle of the two, Manuela on his right, with Hanneman on his left.

"How are you enjoying your time at the academy, thus far? I hope you have found our halls brimming with the vitality of well-intentioned souls." Lady Rhea continued. Seteth crossed his arms. He expression was a mix of discontent, slight anger, and resignation.

The green-haired advisor began to speak to Byleth. "Hm. I suppose it is time for you to take charge of one of our three houses of students. I must note that I am personally against entrusting someone as lacking in trackable history as yourself with such a task, but it is as the archbishop desires."

After Seteth said that, Manula cleared her throat. She then said to Byleth, "The Black Eagles, the Blue Lions, and the Golden Deer...All so different. I hope you've made it a point to get to know each of them."

"I spoke with some of them." Byleth said truthfully under Manuela's piercing gaze. Manuela then smiled. Hanneman turned to Byleth. "Since you are new here, we have decided to allow you first pick. Manuela and I will take charge of the remaining two houses."

'What house should I teach?' Byleth thought to himself.

Byleth had to admit that he felt drawn to Edelgard, but something didn't sit right with him. Maybe it was because of her always evaluating personality. Her house also was mostly nobles, and most of them had very different personalities. Byleth and his family always spent a lot of time in the Empire. Whatever it was, Byleth had a feeling that Edelgard was a part of a greater whole.

Dimitri was the leader of the Blue Lion House. He seemed sincere, but he said that he had a troubled past. That probably caused the lingering darkness that Byleth sensed lurking beneath Dimitri's sincere exterior. The Blue Lion House also seemed to have a strong camaraderie with the other students in their house. Byleth and his family also spent a lot of time in the Kingdom.

Lastly, there was the Golden Deer House, which Claude was a leader of. Claude has a striking smile, but it doesn't reach his eyes. That probably meant that Claude was very cunning and mysterious. Also, Byleth didn't spend all that much time in the Alliance, but he did know some customs.

When Byleth was at a standstill, his promise to his father rang throughout his head. Byleth's promise to Jeralt was that he would always protect and look after his siblings. With that, Byleth knew his choice.

"I choose the Blue Lion House." Byleth said. Lady Rhea nodded while saying, "Your heart has made its choice, then. All I ask is that you guide these open minds with virtue, care, and sincerity."

"They are all promising youths who bear the weight of Fódlan's future upon their shoulders. I hope you appreciate what an honor it is to lead them." Seteth said.

Lady Rhea then turned to the other two professors in the room. "What do the two of you? Which of the remaining two houses do you want to teach?"

"Manuela, I will allow you to pick your house of choice. I am fine with leading either of the two houses." Hanneman told his colleague.

Manuela smiled. "Why, for once you act like a gentleman. Very well, I will pick the Black Eagles."

"Then I will settle with teaching the Golden Deer." Hanneman said afterwards.

"Excellent. I pray the three of you will devote yourselves to teaching the youth of Fódlan. They are in your hands, professors." Lady Rhea told all if the professors in the room. All of them nodded. The sound of footsteps then interrupted the meeting.

"Brother?" A young girl's voice said. Everyone turned to see a young girl with light green hair and green eyes enter the audience chamber. She was wearing a uniform similar to the ones of the Officers Academy, but not the same. At the gazes that she got, the girl said, "Oh! I am so sincerely sorry! I did not mean to interrupt."

"I am in the middle of something, Flayn. Is it urgent?" Seteth said with a gentler tone of voice than when he spoke to Byleth.

Flayn shook her head. She then saw Byleth, and she asked, "No, no, it's nothing. More importantly...Who is this?"

Seteth reluctantly answered, "This is our newest professor at the academy."

Flayn's expression lighted up. She then said to Byleth, "Oh my! A new addition to the Officers Academy! I am so very pleased to meet you, Professor. I am Seteth's little sister, Flayn. I am so happy to make your acquaintance."

Once Flayn was at Seteth's side, he then began to speak to Byleth again. "Let is focus on the topic at hand. There is something you should be aware of. In a few days' time, there will be a mock battle between the three houses, intended to gauge the current progress of students. We will be using this battle as an opportunity to ascertain your own abilities as well. Please do not disappoint the archbishop. That is all."

"Understood." Byleth said. Lady Rhea then dismissed everyone.

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24th of the Great Tree Moon, Imperial Year 1180

When Byleth arrived at the Blue Lions classroom, he stopped to look at the outside of the classroom. On either side of the classroom, there was a light blue flag with a darker blue lion on it. He then pushed open the doors. Byleth saw a group of students in the middle of the room.

The members of the Blue Lion House heard the door open, and they turned to see Byleth walking in. Blythe gasped happily and jumped, while saying, "Yes!"

Dimitri chuckled at the turquoise-haired young woman's behavior. Celine shook her head with a soft smile on her face. Besides Dimitri, Blythe, and Celine, Byleth did not know who any of the Blue Lions students were.

A girl with light orange hair had a surprised expression on her face. "Wait! Does this mean that our new professor is... No, I really can't believe it! Oh, I am so sorry, Professor! You just look the same age as the rest of us, and... Oh, and I'm sorry I just said that too! I really must watch my tongue..."

"I don't mind if you treat me as a friend." Byleth replied. The orange-haired girl then said, "You say that, but...I just don't know about all of this!"

"Annette, I'll admit, it doesn't sit well with me either." Dimitri spoke up all of a sudden. He then said to Byleth, "After all, we wish to show you due respect."

"Sure. But, if the professor says it's OK, shouldn't that be enough? That is...if Your Highness can consent to such a thing. After all, we're already speaking this way to our future king, so we may as well relax our speech with our professor too, right?" The red-haired young man added.

"Well, we're not in the Kingdom, so it only goes to follow that we should all speak companionably...I concede. If the professor says it's fine, we ought to accept that kindness gratefully." Dimitri said. The blonde-haired young woman looked down, and then looked back up while saying, "As for me, I'm not sure I can manage..."

"You don't have to force yourself if it's too difficult." The pinkish-blonde haired student said. She then turned to Byleth, and Byleth recognized her to be Mercedes. Mercedes then said, "You're fine with that too, right, Professor?"

Byleth nodded. The blue-haired young man then said to Byleth, "Come to the training ground later. There, you will show me what you're capable of."

"You aren't wasting any time, are you, Felix?" Dimitri asked the blue-haired student. He then said, "As it were, count me in for any such battle."

"Hmph." Felix responded.

"Same with me." Celine said at the same time that Blythe said, "Count me in for that!"

"Pardon me, but I would also love to observe you in battle, for future reference." A gray-haired teenager spoke up. He then continued to speak to Byleth. "If that's okay with you..."

"Ashe," Dimitri said to the gray-haired teenager. The blond then continued, "I won't have you speaking of merely watching. You should join us as well."

"If you get injured, simply just say the word and I'll patch you up straight away!" Mercedes told the group. Blythe smiled while saying, "I'll help too!"

"Your Highness. Do take care not to go overboard." A white haired student said to Dimitri. Dimitri replied, "You worry too much, Dedue. I'll be fine. I promise."

"My companions! Is there not something inherently wrong with crossing blades as a way to bond with each other?" The red-haired student told his fellow students. The blonde-haired young woman then spoke up. "Huh, I never thought of it that way. Well, if that's how you feel, Sylvain, I suppose you'll just stay behind while the rest of us are at the training ground?"

"Ingrid, my dearest friend! You really are too harsh on me." Sylvain told Ingrid.

"Well then, Professor, what do you think?" Dimitri asked Byleth. He then continued. "As you can see, the Blue Lion House is a lively bunch, but you'll find none who work harder. I'm certain that we'll cause our fair share of trouble, but I'm very much looking forward to the year ahead."

Byleth nodded. He then showed his students to the training grounds. Blythe, Celine, and Dimitri were at the front of the group of students, with Felix and Annette at the rear.

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Byleth and the Blue Lions arrived at the training ground. The teal-haired professor opened the door, and walked through, his class following behind. When the door closed after Felix walked through, Byleth walked to the center of the training ground.

After Byleth got to the center of the training ground, he cleared his throat. "I am Byleth Eisner, and I am your new professor. Now that we're all at the training ground, I am going to group you all up in accordance to your weapons. Close range weapons with others close range weapons, and ranged weapons and magic with each other."

"When can we see you in action?" Felix asked with a bit of impatience. Without missing a beat, Byleth replied, "That will be after this exercise."

Byleth the assigned the groups."The groups are..."

"Dimitri, Dedue, and Felix." Felix made a noise of discontent.

"Sylvain and Ingrid." Sylvain put his arm around Ingrid's shoulders, and Ingrid pushed his arm off of her shoulder.

"Blythe and Celine." Both girls high-fived with a smile on their faces.

"And the last group is Annette, Mercedes, and Ashe." Annette put her arms around the both of them with a wide smile on her face.

"I will be walking around, observing how you do. After this exercise, we will start another one." Byleth told the class. He then told them to begin.

Everyone that used a weapon then grabbed a training weapon of choice. Even the people who used magic grabbed a training weapon because of the standards of the Officers Academy. Every student had to be assigned a weapon.

Ingrid was gripping her lance, when Sylvain grabbed her shoulders. She looked at him. The blonde then shook off Sylvain's hands, and swung her left arm backwards, near Sylvain's face. After that, Sylvain grabbed his lance, and him and Ingrid began to spar.

Ashe put his bow in front of him, and pulled the string. Annette went and put a target in front of Ashe. Ashe let go of the string, and Annette used a wind spell to attempt to make the arrow go off target. Even with the wind, the arrow landed in the center. Mercedes watched with a watchful gaze. She then picked up her bow, and shot at the target, though not as accurate as Ashe was. Annette celebrated with a smile.

Dimitri, Dedue, and Felix all grabbed their training weapons. Dedue was hesitant with fighting Dimitri, but, Dimitri eventually convinced Dedue. The shield then rushed forwards with his axe, and Dimitri raised his arm to block the blow with his lance. The blond-haired prince then saw Felix coming towards him out of the corner of his ice blue eyes. He then took away his arm, moved to the right, and then jumped backwards just in time to avoid Felix's swing. Sweat was seen coming from Dimitri.

Blythe was looking at Dimitri when she saw a movement out of the corner of her eye. She sidestepped to see Celine thrusting her sword forward. Blythe looked at her adoptive sister with a smirk, the blue-haired girl also smirking back. Celine then ran forward, trying for a low slice on Blythe. Blythe jumped, and landed by Dimitri, who had just dodged another attempted strike from Felix. Both Blythe and Dimitri smiled, and then went back to their respective sparring matches.

Byleth was slightly impressed by the display of the Blue Lions, but, he could find some areas of improvement for each student.

Dimitri could work on his footwork, because Byleth could see him swapping the feet for his strikes a few times. Dedue could work on the speed of striking enemies, although he is probably hesitating because it's Dimitri. Although Felix seemed like he was fast, he could work on getting faster. Sylvain, Ingrid, and Ashe could all work on the attack power when they use their weapons. Mercedes, Annette, and Blythe could work on the attack power of their magic. And Celine and Mercedes can work on their accuracy.

Byleth decided that the class was ready to move on to the next exercise. He then said, "Alright, time to move on to the next exercise. Gather around."

All of the Blue Lions gathered around Byleth. Once Byleth saw that he had the attention of every member of the Blue Lions. He began to speak. "Now on to our next exercise. Earlier, Felix questioned when you all would see me in action. Well, that time is now."

He had the student's undivided attention when he said that. He continued. "I am going to measure how you all work as a cohesive unit. All of you will be going against me. Dimitri, since you are the house leader, you will lead."

Dimitri nodded. Ingrid had a confused look in her eyes. Why would the Professor want to go against everyone at once? "Are you sure, Professor? That seems like a lot of people to take on."

Byleth told Ingrid that he was sure about this. Blythe shook her head while saying, "We're going to need the numbers. Neither Celine or I have been able to defeat him. I admit, the outlook looks grim, but we might be able to defeat him with numbers."

Every member of the Blue Lions besides Blythe nodded. Dimitri then grouped the Blue Lions into a part of the training ground where Byleth could not hear them.

On the other end of the training ground, Byleth stood. He grabbed a training sword from the armory. The teal-haired professor then walked to the center of the training ground.

Dimitri was planning how the Blue Lions would approach this situation. He was contemplating all of his possible strategies. After a while, he decided to tell the Blue Lions the plan that he thought of.

"Alright. I have an idea." Dimitri said. All of the Blue Lions gathered around. Dimitri then continued, "Here's what I thought of. Ashe, Annette, and Mercedes stay in the back and provide supporting fire and healing. Sylvain, Ingrid, and Celine stay back to guard them. Felix, Dedue, Blythe, and I will engage the Professor. Blythe, if things start to go awry, switch to a supportive role."

Everyone nodded in agreement. The Blue Lions then walked to Byleth. Byleth saw his class approaching his current location.

"You all ready?" Byleth asked once the class stopped. Dimitri nodded to show that the class was ready. Byleth then said, "Once I give the signal, we will begin."

Byleth then began to back away from the class. He got into a ready stance. The class did the same. Byleth swung his sword down.

"Now!" Blythe told the Blue Lions. "That's the signal!"

Everyone then got into their positions. Byleth observed them.

'Impressive.' Byleth thought after seeing the formation. 'A vanguard force in the front, with the remaining units in the back. Wait, the flank is open...'

Byleth then ran forward, past Blythe and her group. Felix tried to stop him, but Byleth just deflected Felix's strike without looking. Ashe was shooting arrows at Byleth, but he narrowly missed every time. The gray-haired teen then realized what they did wrong.

"The flank!" Ashe exclaimed.

It was already too late. Byleth had already took Annette out of the battle. Mercedes raised her bow up in defense, but Byleth disarmed her, and also took her out of the battle. Ashe fired one last arrow before he was disarmed. The arrow didn't do a thing to Byleth.

The teal-haired professor then turned around. Sylvain, Ingrid, and Celine saw him turn around. Byleth swung his right foot at their feet. Celine jumped back to where Dimitri and the others were. Ingrid and Sylvain jumped too, but, Sylvain landed off-balance. Ingrid stood in front of Sylvain, to no avail. Byleth disarmed both in one swing of his sword.

Blythe, Dimitri, Dedue, Felix, and Celine were the only ones left. Byleth shot forward, towards Dimitri at a blinding speed. Dimitri was surprised at how fast Byleth moved. All of a sudden, Dedue slid in front of Dimitri, which gave Felix time to run towards Byleth, and time for Dimitri to jump back.

Dedue and Felix swung their weapons from opposite sides. As a response, Byleth backstepped, and swung his sword forward. He disarmed Dedue, and went after Felix. They engaged in a little sword fight, with Byleth the victor. With that Byleth set his sights on his siblings and the House Leader.

Blythe saw that Byleth had his sights on them, and she sprinted forward. With a smirk, both siblings engaged in a sword fight. Byleth swung his sword, and Blythe ducked underneath it. She then jumped above a swing from Byleth's sword, and struck him on his right arm. She landed behind Byleth, who swung his sword again. She jumped back, and landed on her ankle wrong. The turquoise-haired young woman fell with a pained gasp.

Blythe could only watch helplessly as Byleth ran towards Celine and Dimitri. Both of them landed a blow on Byleth, but they were eventually disarmed.

Once he finished, Byleth sheathed his training sword, and walked towards his sister, who was still on the ground. Byleth asked his sister, "You alright? I saw you land wrong."

Blythe shook her head. Byleth then walked to his sister, and put his arm around her shoulders. He then helped her up, with Blythe leaning on her brother heavily.

Mercedes walked over with the rest of the class. The pinkish-blonde haired woman then walked over to Blythe. Blythe felt healing magic fixing her twisted ankle.

"Thanks, Merce." Blythe said after her ankle was healed. She then stopped leaning on her brother. Byleth then walked to the center of the training ground, in front of the class.

"You all did good for your first time working as a collective class." Byleth said. He then continued. "A few suggestions, though. Make sure you're not able to be flanked, and attack in numbers."

Looking at the class, Byleth had a feeling that the Blue Lions would do just fine with the mock battle the next week.-------------------------------------------------

A.N. Another chapter completed. I incorporated the Blue Lions training scene to the best of my abilities. Next chapter is the mock battle between the three houses.

Also, anyone who wants to make fan arts or AMVs can do so! Once you complete it, send it to me so I can include it!

Hope to see you in the next chapter!