Disclaimer: I don't own Fire Emblem Three Houses, all rights to the owners.

Right, okay, doing Blue Lion path now, so here's the Blue Lions dealing with Byleth's signature brand of peculiarity.

This was a lot harder because I tried not to repeat the same jokes. I used up all my best ideas on the first chapter, and new material doesn't come easy. Doesn't help that the Blue Lions are overall less drastically quirky than the other two houses, and this style of humor is heavily dependant on the character other than Byleth, whereas Intimidating Instructor puts more weight on Byleth herself rather than the other characters, which is a lot easier to manage.

"Professor…" Felix says slowly.

"Yes?"

"What exactly are you doing?"

"Returning a lost item."

"Usually when people do that, they knock."

"I did. No answer. So I'm going in through the back entrance."

"That's a window."

"Exactly."

"You're not supposed to break into someone's room through the window."

"I'm not breaking anything." Byleth says honestly. "I'm just opening it from the outside."

"With a knife?"

"Yes. My fingers can't get under it, and I need to undo the knot."

"That's not the problem, you shouldn't be using the window."

Byleth pauses to think. "...I should use the top entrance?"

"The top- no! Just wait for them to come back like a normal human being." Felix groans.

"I'm not human. I'm a demon."

Felix isn't sure if he's serious or not. The fact that his professor's expression never changes makes it hard to tell.

"Ah, good, it's open." Byleth pops open the window, and steps inside with practiced ease.

"You cut the knot."

"I'll replace it." He pulls some twine out of his coat.

"You just carry around spare twine for this exact situation?" Felix asks in disbelief.

"Well, not just this… but yes." Byleth murmurs. "I also have a few spare knives, in case the first breaks."

"Anything else you have I should know?" Felix asks sarcastically.

"Canteen, gauntlets, twine, knives (normal and throwing), metal spikes, small hammer, sword, two concoctions, various antidotes, bandages, flint and steel, notebook, and a quill and ink case." He lists off as he places a small blue gemstone on a desk. "Also, jerky. Want some?"

"Pass." Felix is sorry he even asked.

Byleth casually replaces the torn string that ties down the window, steps out, and pulls it down. He pulls out something else: a small, fancy-looking feather.

"Is that another lost item?"

"Yes."

"...exactly how many more do you have?"

"A dozen."

That's a lot of window strings he's going to be replacing… and Felix makes a mental note to leave his own window unlocked from now on.

###

"Ack, goddess, poison!" Sylvain coughs as he grabs for his water. "Augh!"

"It's not that bad…" Annette mutters sullenly as the man guzzles down the drink. The two of them are startled by Byleth suddenly rising from his seat with a loud grinding noise and him leaping over the table next to Sylvain.

"What kind? Do you know?" Byleth asks, pulling a number of small vials out of his pockets. "I have a rotberry antidote mix, and some crushed blackleaf-"

"Spice!" Sylvain coughs, slamming down his glass on the table. "How much did you put in that Annette?!"

"Spice? Haven't heard of it..." Byleth mutters rapidly. He stops suddenly, and his head snaps to look at Annette. "You did this?"

"W-Well I didn't mean to add that much-" She's cut off by the man suddenly grabbing her by the collar, and hoisting her up into the air with one arm. "Wha-Wha-Whaaaaaa!"

"Tell me what you used, now." Byleth's voice, usually flat, has a clear hint of steel and obvious threat.

"Bu-But-"

"NOW." Everyone in the mess hall now has their eyes fixed on Byelth, watching with a mixture of confusion and horror.

Annette is visibly shaking. Her trembling hands clutch at Byleth's own, trying to pry it off her collar. "I-I j-just used s-some jalapeno d-dust! J-Just a little!" She whimpers. "F-For seasoning!"

Byleth tilts his head, and blinks slowly. "That's not poison."

"Ah, poison, oh, that was an exaggeration professor!" Sylvain says rapidly. He has a winning smile on now, but the way his eyes dart around makes it clear he's not calm at all. He puts a hand on the arm holding Annette in the air, slowly getting his teacher to lower her. "Not actual poison! A joke! Everything's fine! Put her down… please?"

Byleth does so, slowly. "You're not harmed?" He asks Sylvain.

"Well, my taste buds may be a bit singed, but it's really nothing!" The redhead insists. Byleth releases Annette, and Sylvain gently grabs her under the arm to stop her from collapsing. "It's just a misunderstanding professor. I appreciate your concern, but Annette has done nothing except be a poor judge of how much spice goes on a dish."

"Oh." Byleth says. "You really should be more clear."

"No, you just don't understand hyperbole, or metaphor, or literary devices of any sort." Sylvain sighs. "You must be a riot with the ladies."

"I do not riot. If I want something, I take it… or buy it, or ask for it, or all three. Not necessarily in that order." He pauses. "Why would I supposedly riot only with women? Are they known to be good at it?" He stares at Annette. "Do you riot?"

Annette mutely shakes her head.

"And you made my point." Sylvain sighs. "Professor, perhaps you should just go back to your food."

"Are you sure?"

"Yes, very."

"Okay…" He says slowly. "If you get poisoned again-"

"I wasn't poisoned." Sylvain interrupts firmly.

"If you actually get poisoned-"

"I know who to call, yes, fine, shoo." The man says, uncharacteristically brusk. "Go."

Byleth stares for another minute, eyeing the two of them (Sylvain pointedly positions himself in front of Annette, just to give her a bit of a shield from the professor), before slowly moving back to his seat.

"I-I'm so sorry." Annette says quietly.

"No, it's fine. The professor is just… dramatic." Sylvain sighs, and pats her on the shoulder reassuringly. "Do you want to go somewhere else to recover? Maybe some tea in my room?"

The girl is shaken, but not that shaken. "Nice try." She smiles.

"Tsk…" Sylvain feigns disappointment, but he's inwardly relieved that Annette recovered so quickly.

###

Ingrid isn't sure if she's impressed or disapproving. There's few people who can go toe-to-toe with Dimitri. Usually it takes a two on one to get an even fight with him, but Professor Eisner is managing quite well… however, he's not really fighting fair.

Scratch that, he's pulling out every dirty trick short of eye gouging.

"Gah!" Dimitri sputters as Byleth whips out his canteen around, the top popped off, and splashes water in the boy's eyes. He still manages to raise his spear to block his professor's overhead strike, but he's also forced to back up as he tries to shake the water out of his vision. "Professor!"

"Bandits won't fight fair." The man says flatly. "And you never know when someone will decide to ignore what's supposedly "fair". Better to use everything you have, and expect your foe to do the same."

"There's no honor in that!" Dimitri protests. "We're no better than bandits if we-"

He's cut off by Byleth punching him in the face. It's a move that should never have happened, it's completely reckless and easily punishable, but the boy is so surprised that he doesn't think to counter it until the window of opportunity has passed.

"See?" The teacher says as Dimitri blinks in shock. "I only got away with that because you're thinking in terms of a fair fight. Don't. Be ready to counter anything, and use anything to your advantage."

'I must protest Professor!" Ingrid interrupts. She's sitting on the sidelines along with the rest of the class, but she can't remain silent. "If we fight by that creed, then we are no better than bandits!"

"Bandits are not immoral because of how they fight, they are immoral because of why they fight." Byleth responds curtly. "There is no good or evil in combat, only what works and what doesn't."

Ingrid purses her lips. She doesn't agree with that at all. What sort of teacher encourages their students to splash water in their enemy's eyes? Or to sucker-punch someone when they're not expecting it? "Yes, it's effective, but it's also quite nasty and unbefitting someone as respected as a knight."

"Better unrespected than dead." Byleth responds. He deflects a thrust from Dimitri with his sword and promptly kicks the boy in the shin to punish his recklessness. The follow-up sword swipe smacks Dimitri in the head as he hastily, foolishly, lowers his guard to protect his lower body. "Dead."

Dimitri tenses, and for a second Ingrid thinks he's going to shout at the professor, but he releases the tension a moment later and lets his spear tip drop to the ground. "You're quite the fighter professor."

"I would hope so." The professor states. "As I'm trained and tested mercenary, I'd consider it a failure on my part if I couldn't beat my own students."

Dimitri, and everyone else for that matter, decides not to comment on the fact that he basically just insulted the entire class. Instead they nods mutely and let him continue with the lesson.

###

"..."

"..."

"..."

"I like you."

"Erm… thank you, Professor."

###

"Are you a demon?"

"Um… not that I know of." Ashe says hesitantly. "Why…?"

"I have a title." The man says. "The Ashen Demon. I wondered if you were the same as me, because your name is Ashe, so I asked if you were a demon, because then you would be an Ashe demon."

Ashe considers that a very strange way of thinking, but he doesn't say it aloud. "Well, I'm sorry to disappoint Professor. I'm very human."

"That's fine. Demons are dangerous. I would know."

"You would?"

"I am a demon."

Ashe eyes the man warily. There's no change in expression or inflection, so he doesn't know if Byleth is joking or not. He decides to just not address it and change the subject. "So, what are you doing here professor?"

"Scouting." The man says, and hops up on the short wall that overlooks the cliffside. Ashe resists the urge to reach out and pull him back down. That looks dangerous. "For a lesson."

"What lesson?"

"Scouting, observation, navigating difficult terrain." He responds curtly.

"Aren't we learning how to be knights, not scouts?"

"I am teaching you how to be competent soldiers in any capacity." Byleth corrects. "I teach every aspect of warfare, not just combat. Perhaps, as most of your classmates for nobility of some sort, they will never be sent on scouting missions as they are considered too vital, but it is important to understand the concepts behind it anyways in case you are to ever order a scouting mission yourself. Knowing how scouts can abuse terrain to their advantage is just as important as being able to do it yourself. Information is power just as much as fighting strength is."

Ashe can understand that. It's like a good robbery. You can have all the stealth in the world, but if the homeowner is actually home when you make your attempt, you're in for trouble. Knowing when they're gone is just as, if not more important, than any actually sneaking skills one has. "That makes sense. You can be as good a fighter as you want, but if you don't know you're fighting in a marsh until you actually start fighting, you're in trouble. Even if you aren't doing the scouting, there's value to knowing how it works and its benefits."

"Exactly." He nods. "Do you have experience with this?"

"Well…" Ashe says slowly, reluctantly. "I used to be a thief."

"Ah." Byleth nods. "Scouting is very important for a good theft. Also target selection, blending in, knowing how not to draw attention. Good skills to have."

Ashe wishes he never had to develop those skills at all. "Yes, well… I didn't obtain them through schooling though."

"I assumed not." Byleth says. "Hmm… I have a question."

"Yes?"

"If I wanted to steal from the monastery, how would I do it?"

Ashe raises an eyebrow. "Depends on what you want to steal."

"Something from the archbishop's room."

"Hmm…" Ashe purses his lips and thinks. "I'd have to observe the guard shifts for a few days, and then find a spot to where I can observe Rhea's patterns. Alternatively, I can wait for a ceremony where I know Reah will appear, and attempt to sneak in then, though it's a bit more risky because the guards might have changed shifts for a special occasion."

Byleth nods approvingly. "Very smart. However, you missed one thing."

"What?"

"Your fellow students. You're only paying attention to the guards, but the general crowd or servants can be a danger as well. In a market it's unlikely the crowd will care about one person, but here most students have a measure of combat training, and are more likely to raise the alarm or fight you directly if they see shady behaviour."

"Ah." Ashe nods. "I see… but Professor."

"Yes?"

"Why did you want to know?"

"Simply a mental exercise." Byleth says. "It's good training to make a plan of attack or infiltration for any location, as well as plan how to escape any room they're in or take out any given person, or all people, around them."

Ashe blinks. He understands the idea behind it, but… "That's a scary way to think professor. Have you considered how to eliminate your students as well?"

'Of course." Byleth nods. "I could have slid a knife in your back when you were reading, or any time while we were talking, or I could have grabbed you and thrown you off the cliff, or thrown a knife at you as I'm leaving, or used one of the loose rocks here as a projectile so I could follow up with a knife, or even rushed you for a fistfight considering you don't seem to be armed and aren't particularly strong. I could have waited for you to go back to reading before knifing you, or abused your trust of my by shouting at you to watch out for something behind you and stab you when you're turning around."

A chill runs down Ashe's back. That's half a dozen ways to kill him rattled off like a shopping list.

"Another option would be for me to walk away and wait around a bend, and stab you then. I could get a bow from the armory if you continued to read, and shot you from any one of the windows or roofs around here. I could even find something heavy, go up on the roof behind you, and just drop it on your head. Maybe an anvil. I could just set a trap in your room at the doorway, a crossbow with a string around the trigger that fires when you open your door. Or-"

"I get it! I get it!" Ashe says hastily. He doesn't want to hear about the myriad of ways he could die within the next hour. "That really is scary professor."

"Such is the reality of war. One must see every opportunity, both for them and against them." Byleth replies duly. "I encourage you to look for ways to eliminate anyone you see. It's good practice."

"Professor…"

"Yes?"

"That is not something you should be suggesting to one of your students, or anyone for that matter."

"But it is important for a warrior to know many methods to eliminate-"

"I know! But I don't want to consider ways to kill my friends." Ashe says firmly.

Byleth blinks. "You don't?"

"No!"

"How odd."

"Professor, I hate to tell you this, but you're the odd one."

###

"Why so shy Professor?" Mercedes murmurs as she passes a slice of cake. "It's unlike you."

"I am not shy." Byleth responds bluntly as he accepts the plate. He takes a bite, and then blinks rapidly. "Chocolate?"

"Indeed. Do you like it?"

Byleth nods mutely. His expression is no different, but he's eating notably faster than usual.

"I've noticed that you've been noticeably more distant lately, is something the matter?" Mercedes says in a soft voice.

"I am restraining myself."

"I can see. Why?" Byleth, as strange as it may sound, is usually quite affectionate towards her. He's oddly fascinated with her hair, and usually begins any interaction between the two of them by patting it, or occasionally lying his head on it. Mercedes knows there's no malice behind either action, hence why she is more than happy to allow them despite the general strangeness.

"You told him not to."

"Him?"

"Yes."

"You'll have to be more specific Professor. I speak to many men on a regular basis."

"The one with the hat and the black curls. You spoke with him outside the cathedral two days ago just after midday, off to the side of the main entrance." Byleth recounts.

"Ah." Mercedes smiles grows a bit strained. "Sir Gallberry. What exactly did you hear?"

"I could not hear initially over the noise of the crowd. I saw him place a hand on each of your shoulders, and then you informed him that a man of his station was not allowed to do such a thing."

"I did say that." Mercedes nods. That was an uncomfortable interaction. She really wishes she could do away with suitors entirely sometimes… "What does that have to do with your current behaviour?"

"He was a man of some status, yes?"

"Yes. A wealthy merchant, like my step-father." The lady's mouth purses a bit. "I think my father may have suggested he detour here, hoping I would take a liking to him. He'll be rather disappointed…"

"You said a man of his station could not touch you. It stands to reason then that a man less than his station also could not do such a thing. Such as me." Byleth says. "A simple, logical deduction. I must have been too intimidating to tell off, hence why you never told me to." He pats his hip. "I do carry a sword. Swords can be scary."

Mercedes slowly shakes her head, with a smile re-emerging on her face. "Professor… it is a rare occasion that I would describe you as anywhere close to scary. You are peculiar at worst."

Byleth's eyes squint as he thinks. "So you were tricking me for some unknown benefit… perhaps to gain a favor later? So I would be lenient on you…?"

"Or…" Mercedes says slowly. "Perhaps I don't mind?"

"That can't be right. I am of lower status than Dullberry, your no touching rule should apply to me as well."

"Professor, I told him that because I did not like him." The lady laughs softly. "Why are you so quick to assume I am manipulating to you? Perhaps I simply do not mind."

"Or your plan failed, so you were planning to poison me today with cake."

"Professor… you are quite paranoid."

"Vigilant. Not paranoid."

"I respectfully disagree."

"So the cake isn't poisoned?"

"No. Why would you eat it if you though it was?" She asks curiously.

"Because it's good cake." Byleth says honestly. "And I had several antidotes beforehand as a precautionary measure."

"Please tell me that is a joke Professor."

"No."

"Oh dear…" She sighs, and picks up her tea. "How much will it cost to replace those?"

"Several hundred gold."

Mercedes almost chokes on her tea, and she has to put the cup down before she drops it. "P-Professor, you used a several hundred gold's worth of antidotes simply so you could have cake?"

"Yes." He seems perfectly unabashed about the decision. He's also finished his current slice. "Can I have more?"

"Yes, go ahead." She sighs. On one hand, Mercedes is mildly worried about his man's level of paranoia, but on the other she's flattered that he's willing to waste several hundred dollars just to have some of her cake. It's a compliment to her cooking… although probably the strangest compliment she could possibly imagine.

"So Marshmallow… I can touch your hair?"

The girl resists the urge to roll her eyes. "Yes Professor."

He wipes a hand clean, and reaches out and does so. His expression still doesn't change, but his contentment is still obvious. "Soft…"

Mercedes smiles. It's strange how normal this interaction has become, so much that she noticed it's absence over the last few days. "Thank you Professor. I take special care of it."

"Good. Hair is a dangerous weapon." He says sagely. "You could hide a dagger in here, or a message, or something else of importance… like poison."

Mercedes just shakes her head. "You really are paranoid Professor."

###

"Professor."

"Yes?"

"There are easier ways to get a book."

"There are?"

"You can ask for it."

"I can?"

Annette chuckles in amusement. "Yes, you can."

"But it belongs to the church."

"You're part of the church."

"I am?"

"Yes… now please get off the wall. People are worried you're going to fall." She says. "Also, you probably shouldn't be staring at people through a window."

"But I'm not allowed in the private library."

"Yes, you are. You're part of the church."

"Oh, right." He drops down from where he was perched, grabbing onto the window still, and landing on the pathway next to her.

"Why were you up there anyways?"

"There's a book I want to read. I thought I couldn't get it because I couldn't go in the library, so I waited for someone to take it out so I could read it through the window."

"That's… wow." That has to be the most unlikely-to-work plan she's ever heard, and she's heard Sylvain make some really bad plans concerning women before.

"Because I thought I couldn't go in the library, and therefore take out the book, but there's no rule about being outside the library, or reading the book if someone else took it out…"

Annette shakes her head. "Has anyone actually taken out that specific book?"

"Not yet."

The girl shakes her head. "You're very persistent professor."

"Thank you."

"Would you even be able to read the book from the window?"

"Probably not." He says calmly, as is that isn't another massive flaw in his plan.

"Then why did you bother?"

"I have spare time."

So he spends his spare time peering through a window-still rather than doing a hobby or something? She'll add that to the list of weird things he does (and there is a list, Sylvain makes it).

"I could never spend time doing something like that…" Annette murmurs. "I'd never be able to just sit and wait for that long, I'm not used to doing something so unproductive for that long."

"It wasn't unproductive."

"Why not?"

"Endurance practice for hanging onto ledges."

"And how often do you actually use that skill?" She asks with an amused smile.

"Often, when I had to take back or top entrances on missions." Byleth says honestly. "Sometimes, I had to use just one hand, because I had to open the back entrance with the other."

"Oh." Annette meant that as a joke, she didn't expect he actually had a use for that sort of practice. Another thing for the list she supposes. "Also, professor…"

"Yes?"

"Why do you respect the privacy of the church, but not your own students?"

"Pardon?"

"You break into our rooms, routinely."

"You all keep losing things. I return them." He says simply, completely missing the point. "That is what you're supposed to do when people lose things, right?"

"Well you're supposed to return it to them… not their rooms."

"Why? It's easier to put it in its place rather than track someone down."

"But that's illegal!"

"So is walking across a street in a city while not at a crosswalk, but people do it all the time."

"Professor, breaking into someone's room and jaywalking are two very different things."

"Yes, but they have a similar level of importance."

"That is the exact opposite of what I just said."

"No." Byleth disagrees. "You said they were different, which they are. I said they were of similar importance, which they also are."

"I…" It takes a minute for Annette to understand what on earth he's talking about. "I don't mean they're literally different actions-"

"But they are."

"I know that! I meant to say that they're of different levels of importance."

"Why didn't you just say that?"

"I did!"

"No, you said they were different. That's different."

Annette decides she's had enough of trying to argue linguistics with a madman. "I'm… going to my room to study."

"Okay."

This chapter was a lot harder than I thought it would be. Like I said at the start: this Byleth doesn't bounce off the Lions as well as the Eagles, and I used all my best material in the first chapter. The Lions are also feel less drastically quirky, which is what makes characters like Bernadtta work so well with him (also, I just tend to work better with quirky characters. Almost every Blue Lion is the straight-man, the "Edelgard" of the dynamic so to speak, rather than a "Bernadetta" who facilitates further humor.

Except Marshmallow. Marshmallow was strangely useful in facilitating Byleth's strangeness, despite being probably one of the most grounded characters.

Hopefully the Deer will be easier to work with, and hopefully Intimidating Instructor will do better justice to the Lions than this did.