Set after the events of Season Six.

Riven is trying to forget about Musa, focusing only on his training and his position as a Professor at Red Fountain. Unfortunately, his personality hasn't improved, and very few students willingly come to him for training due to his extraordinarily high standards. Headmaster Saladin decides to assign him a student to act as their mentor, a student who has shown great promise in swordsmanship.

What Saladin didn't tell him, was that this student was a girl.

As if that wasn't enough, a new threat appears calling the Winx and their Specialists back into action – a threat that risks the destruction of all magic.

TL;DR: After S6, with the assistance of his reluctantly accepted apprentice and new Red Fountain student, Riven must help the Winx and his squad protect the Magical Dimensions… again.

Chapter One: Regarding Riven's Teaching Skills (Or Lack Thereof)

"You're an incredibly talented warrior Riven," Professor Saladin began once Riven sat down, "But you are not good at training others to become the same."

This was the third time Riven had been called into the Headmaster's office to discuss his teaching ability. It was only three weeks into the new academic year.

The first time, Professor Saladin encouraged him to be more understanding towards the students who went to him for extra training, who were struggling with a form or wanted to learn from a warrior known for helping save the Magical Dimensions – "Your skills are worlds ahead of the students you teach Riven, and they will have difficulty keeping up with you. You need to exhibit some level of patience with them, or they will never be able to learn from you."

The second time, Professor Saladin told him about an informal 'fight club', as none of the students had called it, that had been formed – "Students claim to be learning more from each other than they do from one on one training with you, Riven. They say that is given the choice between taking lessons with you, or cleaning out the dragon stables, most students would volunteer for dung duty. No one volunteers for dung duty."

Riven had just scoffed. Each year, the freshmen seemed to be getting softer and softer. They couldn't comprehend the simplest of instructions. They were insulted by the softest of criticisms. The simplest weapon forms seemed beyond them. And don't even get him started on his Tactics and Strategies class – his only regular academic class for seniors that he covered once a week – the students refused to talk! He would ask them questions and they would just sit there, dumb and silent.

Interpreting his scoff correctly, Professor Saladin continued, "You were the best strategist in your graduating class. Your swordsmanship is second only to Sky. You have so much knowledge and experience that your students would benefit greatly from, but you seem incapable of sharing it." He leaned forward with fingers steepled. "I want you to remain a teacher at Red Fountain Riven, but if you do not show me that you are willing to try and fix your attitude, then I will have to let you go."

He couldn't believe it. "What?! You would kick me out of your school because a couple of kids can't handle my classes?"

"I would remove you from teaching because when the entire cohort was asked who the worst teacher they ever had was, almost every single one of them agreed that it was you."

Riven stood with such force that his chair went flying. "You can't get rid of me!"

Professor Saladin stood in response. "I don't want to get rid of you Riven. You have so much potential as a teacher, and so much to learn as one. You just don't have the patience or attitude to realise it."

He was starting to panic. I don't want to leave Red Fountain. It was his home, the one place he felt truly safe. As much as he hated to admit it, leaving his squad, his family… it would be easier and less painful to pull out his heart. And after losing Musa – after letting her go, and not trying hard enough, and – He couldn't lose anyone else. He couldn't lose this too.

With a wave of his hand, Professor Saladin sat back down. Riven retrieved his chair.

"I am going to give you one last chance to improve. If you do not succeed in the given task by the end of the school year, you will no longer be a part of Red Fountain."

Riven swallowed painfully. "What do I have to do?"

The smile on Professor Saladin's face, if looked at in a certain life, could be considered pleased. To Riven, it looked positively sinister, and made his stomach sink to his toes. "There is one student in Red Fountain who doesn't see you as the worst teacher. They will be assigned to you as your protégée – they've shown great promise in swordsmanship, can be quite a crafty thinker when they put their mind to it, and indeed, they remind me a little of you in your first year. You are going to act as their mentor, tutoring them in any classes they have difficulty in, things like that. I would advise working on an accelerated course in weapons handling. Of course, you can ask your squad for assistance in their respective areas of expertise, but you are to be their main trainer.

"Your ability as a teacher will be proven at the end of year exams – I expect your student to achieve suitably high marks, given that they will have a year of one on one training – and I will also construct an extra credit challenge course that they must complete. If they do not, your tenure here will be terminated. If they succeed, I will see about reassigning you to your classes, unless you wish to continue training your student into their sophomore year."

Biting down the urge to scowl, Riven nodded. "Fine. Who's the student?" At least he's getting someone who is essentially a blank slate – fewer ingrained bad habits to deal with.

Professor Saladin's smile widened. "They are a freshman from Ventus Institute. You have leave to train them however you see fit – they had a, how to put it… unusual training experience at Ventus, so they may be a little behind on some things."

Riven snatched the proffered file with a curse. An unusual training experience, huh? So they won't even have the very basics under their belt yet! He wanted a blank slate, not a slate that hadn't even been made yet! He'll have to practically hold their hands through weapons maintenance, physical training – all the things students are meant to know before they come to Red Fountain. And they're mean to have potential? They probably can't even hold their sword the right way round!

"Oh, by the way, your student is also mute – if you can also get them talking consistently by the exams, if they pass, you'll only get the best senior students next year."

The subsequent cursing was loud and foul enough to scare a bird into flight, shock two freshmen into dropping their books, and make Helia look up to the sky in resignation.

"They're waiting for you in Training Room Four – that will be yours to use for the year. Good luck!"

This is going to be GREAT.

Riven tried his best to twist his face into a less terrifying scowl. No use scaring off his new student before they've even started training. Their file was still in his hand – he hadn't looked at it yet. A student's ability was better realised when experienced through a sparring session rather than notes on a page. Especially when it came to students from the Ventus Institute.

Ventus Institute was arguably one of the best schools for warriors in the Magical Dimension. Located in a mountain range on the planet Auris, Ventus prided itself on creating exceptional soldiers. The planet's infantry was often spoken of in reverent tones, their archers were said to never miss their targets, and their skill at dragon wrangling made their mounted cavalry the envy of the Magical Dimension. Every year, five of their sophomore students were chosen by Saladin to complete their training at Red Fountain. They would leave as foot soldiers and return as Generals. However, because of the Institutes' reputation, many of the students had an ego the size of Magix and an inflated sense of their own skill. Riven can remember breaking the arm of a Ventus student back in his first year – he was picking on Timmy because he preferred to hone his technological talents over his physical. Very few people accepted his hand-to-hand challenges after that.

But coming back to the current issue, it was very likely that Riven was going to be stuck with an egotistical, under skilled bigot of a student for a year – and the unusual training thing just stunk of entitlement.

Grumbling under his breathe, Riven pushed open the door to Training Room Four. It was one of the smaller rooms, designed mainly for teachers to maintain their skills, but there was enough space for both him and his student.

A student who was currently facing away from him, running though some of the katas of Form I: Shii-Cho. They weren't doing too horribly, Riven admitted to himself. Their footwork as a little off – Cordata sometimes forgot to take the slighter build of his students into account when demonstrating forms – and they would need to put more power into their swings if they wanted to do any kind of serious damage, but those were small issues, easily fixed. From behind, they reminded him a little of Helia before he cut all his hair off. Pin straight black hair fell from a low ponytail to reach just past their hips. They obviously hadn't had their growth spurt yet, given the narrow shoulders and the fact that they probably wouldn't have reached his chin in height, but that would come in time. Helia was a twig when he started at Red Fountain but look at him now and you'd never think it.

And then the boy turned around.

It wasn't a boy.

"SALADIN!"

The Headmaster looked up with a serene face even as Riven barged into his office mere minutes after leaving. "Is everything alright Riven? You look like you've had a shock."

"What is this?!"

This was the girl he had just dragged across the school by her wrist (her very thin wrist), practise phantosaber, or bokken, in hand. Bright purple eyes looked between Riven and Professor Saladin under a black fringe.

"Hello Celeste," Professor Saladin said kindly. "I see that you've met your new mentor."

The girl – Celeste – slowly nodded. She didn't look entirely pleased by the situation.

"Is this a joke?!" Riven shook the girl's arm, ignoring the way it seemed to shake the rest of her, and said, "Since when were girls invited to train at Red Fountain?"

"Celeste is a special case, and I owed the Ventus Headmaster a favour. I assure you; she is more than capable of meeting expectations – I wouldn't have allowed her to attend if she couldn't."

"I don't care how good she is, she is still a she!"

"Celeste," Professor Saladin emphasised, "Currently holds the highest marks in her grade in the geographical surveillance exercise, was the quickest person in her grade to correctly demonstrate the first three katas of Form I, and has been recommended for further training by the Headmaster of an esteemed Institute. She has every right to be here. If you do not think yourself capable of being professional and training her, you can hand in your resignation right now."

Riven spluttered for a moment. It was bad enough that he was going to have to mentor someone, but he had to mentor a girl? A girl who was…

"You said that she was mute! How can a mute girl learn how to be a Specialist?"

Professor Saladin shrugged. "You are going to have to figure out the best way to communicate between the two of you. Just because you are a teacher now, does not mean you stop learning. Unless Celeste has any objections, you will train her or you will hand in your resignation."

Two sets of eyes turned to the girl. Holding the bokken at parade rest with the tip against the floor and both hands on the hilt, she stared uncertainly between the two men. Riven's hand was still wrapped around her arm, and he let it go with a scoff.

"Celeste? This is your choice – it does not change your situation at Red Fountain. No matter what, you will be trained."

Riven stared at the stupefied girl who was going to decide his continued existence at Red Fountain. Is she going to say yes? Why would she? Who is in their right mind would consent to being taught by me?

Celeste's morning wasn't going the way she expected it to. She'd overheard stories in the halls about Professor Riven's temper, but she'd never expected to see it for herself!

Professor Codatorta had sent her to Training Room Four this morning rather than assigning her a sparring partner – "You're being given to one of the new teachers to train." When one of her classmates (and wasn't that a funny thought, her having classmates), the Professor had growled at them.

"This is a punishment for the teacher, not the student. Or would you rather take her place as Professor Riven's apprentice?"

The class went deathly silent then. None of them wanted one on one lessons with the scariest teacher at Red Fountain.

Said teacher wasn't in the room when she got there, so Celeste took the chance to start practising her form. The bokken felt good in her hand – so much better than the broken ones she was allowed to touch at the Institute. Even if, technically, she wasn't meant to be touching them either.

Celeste didn't technically exist in the Institute.

(Be quiet. Don't let anyone hear you. Don't let anyone see you. If anyone tries to catch you, run. Don't take anything that might be missed. If anyone but Headmaster sees you, you'll be banished)

(And banished means that you'll never see me again)

She was one of those weird secrets. As long as no one had proof that she existed, Celeste could do anything she wanted, including living in a school where only boys were allowed to learn how to fight.

But now she was at Red Fountain, where she was encouraged to fight, and got in trouble if she wasn't seen at certain times, and isn't allowed in the kitchen, because if she wants food, she can get it from the dining room three times a day like everybody else.

It was a bit of an adjustment period, not just for her, but everyone else at the school. Most of the students ignored her, which was fine. Some of them picked on her a little – making fun of her behind the teacher's back, accidently missing their target during blaster practise and hitting her instead, chasing her down the halls to help her practise her evasion – but they were tiny things. She could deal with them. It was easy enough to dodge a stray blaster shot. No one followed her when she jumped over the third-floor balcony, so that was an escape when she needed it. A couple of the students who chased her broke into her room once to mess up her things, but she had so little to mess up that they didn't actually do anything, so that was fine.

The hardest thing for her to get used to was walking down the halls in broad daylight, rather than sneaking down them in the shadows. Celeste had never realised how pale she was until she stepped out into the sun one day with her sleeves up and almost blinded herself. The sun could be so bright, it was overwhelming.

None of the teachers were too worried about her not talking – if they really needed an answer, she'd type it on her tablet and show them. Professor Codatorta didn't even need that. He seemed to be able to take one look at her and immediately know what she was thinking – it was disconcerting to be seen so clearly.

But back to Professor Riven.

Celeste had been so focused on making sure she got the kata right that she hadn't noticed Professor Riven coming into the room. When she turned around, he looked so angry. Apparently, it wasn't because she was using a bokken without permission, like she thought, but because Professor Saladin hadn't told him that she was a girl.

Professor Codatorta was right. This was a punishment for the teacher. And if she didn't say yes to being taught by him, he was going to leave. She didn't know what terminated meant, but she recognised resignation. It meant leaving something you didn't want to leave, like when Professor Da-Vid was kicked out of the Institute. If Professor Riven didn't teach her, he wasn't going to be teaching anyone.

Not many students wanted to work with the temperamental professor – many of them complained about how harsh Professor Riven was, how he busted their arses, and has obnoxiously high standards, and would never give a compliment.

He sounded a lot like Headmaster.

Celeste bowed deeply to Professor Saladin, because that's how you showed you respected someone, by letting them see your back and trusting they won't hurt you for it, before holding her bokken out to Professor Riven, hilt first. She had to communicate her choice somehow, right?

Despite the seriousness of the situation, Celeste couldn't help but smile. I'm going to be trained!

Riven stared at the proffered bokken in disbelief.

Professor Saladin, for his part, looked too amused for Riven's liking. "I believe Celeste is consenting to being trained by you."

With a scoff, Riven pushed against the sword, ignoring the twist of guilt he felt when it impacted with the girls' stomach. "Don't go just throwing away your weapon, you idiot."

She looked at him for a moment, as if committing the words to memory, before giving him a nod so deep it was almost a bow. Riven inhaled deeply before he said anything – Ventus Institute was a very old-fashioned school of training, and gestures of respect such as bowing and scraping were commonplace there. He'd just have to train it out of her, just like every other bad habit she probably picked up.

"Well, you two should go and discuss your schedule – Riven, I have sent you Celeste's timetable regarding the classes she still needs to take, but you are responsible for the rest."

After that dismissal, Riven stalked out of the office with the girl hot on his heels. He didn't say a word until they reached the relative safety of Training Room Four – their training room. On the way he scanned her schedule. He scoffed. Schedule wasn't the best word for it, more like checklist. The only classes he didn't need to cover was Politics and Information Technologies. Every physical class was his responsibility, along with War History and Tactics and Strategies. To be fair, his area of expertise was strategy, and War History was an easy enough class – all you had to do was memorise a few dates, write an essay about when this war happened or why that king killed this king, and you were golden. An attached note said that the curriculum for both classes would be sent to him, and that he would need to ensure his student had enough time to do her theoretical coursework on top of whatever homework he assigned.

His student. Her.

How had he not seen her before now? Classes started three weeks ago. He had covered two freshmen War History classes for a sick teacher in that time. Surely, he would have noticed a girl in the class.

(He didn't)

In the centre of the training room, Riven pulled out a bokken of his own. "Professor Saladin says you have potential – prove it!" With a lunge, their duel began.

Out of all the sword forms Red Fountain taught, Riven preferred Form V: Djem-Sho. It combined Forms II and III into an aggressive style that merged defence and offence into a terrifyingly well-rounded whole. It best suited his 'attack is the best defence' attitude without leaving him open to counter-attacks. Admittedly, it could be a confronting form, and definitely not something a freshman would have fought against before.

The girl was blocking admirably. She had obviously been practising her Form I katas, but some of the tighter, faster movements resembled the Form III defence some of the sophomores had been trained in earlier in the week. Her dodging skills were well developed, avoiding more attacks than she blocked, which given her slighter form, was probably the best idea. She was built for speed, rather than strength. However, she continued to give up ground, Riven backing her around the room. He struck only at every second opening she left in her defence, not wanting to call an end to his test too soon.

After some time though, Riven grew annoyed. "Don't you know how to attack? Or can you only walk backwards?" He snarled, halting his advance. They were back where they'd started, the girl panting lightly in the centre of the room. With both arms outstretched, he sneered, "C'mon, show me that potential Professor Saladin thinks you have."

Something in the girl's face twisted. His first thought was anger – that's what most students felt when he goaded them like this. But when she didn't strike immediately, he waved the hand not holding a sword.

"Are you just going to stand there all day? Fight!"

A second later she lunged into an underarm strike, and as he parried, it hit him. That wasn't anger – it was hesitation.

Then he noticed something else.

Her attack form was so much worse than her defence.

That's all Riven could think about as he parried the, honestly, pathetic attempt of an advance. The girl was tentative in her attacks and slow at taking advantage of any (purposeful) slips in his guard. A fairy could fight better than this!

"I thought you were a warrior!" Riven goaded, "Is this all the Ventus Institute can do? Defend themselves well enough to run away?" He parried another half-hearted blow before launching into a flurry of attacks.

The girl defended herself desperately, feet slipping on the training mats, but Riven wasn't going easy on her this time. He locked her bokken with his own, pressing her wrist against her chest at a painful angle, and with his other hand he begun to poke her in the forehead with one finger. "Look at that! You can't even defend yourself from a finger!"

It only took two more pokes before the girl released a soundless snarl and moved.

With surprising force, the two bokken were twisted and pushed against Riven's chest, driving him back far enough for her to swerve down and under his guard, snapping a bruising kick at the back of his knee. Clearly she was trying to knock him off-balance, following it up with an elbow to his stomach. Riven recovered quickly, landing a sharp hit across the girls' shoulder as she slid past him.

It wasn't until Riven's face almost met the floor that he realised – that lapse in judgement was deliberate.

The girl only came to Riven's collarbone. When she slipped past him, she was far enough under his guard to slide her bokken between his legs and twist, forcing his supporting leg forward and putting enough pressure on his other knee to make him move it unless he wants to risk a fractured knee cap. As he stumbled, she elbowed him in the spine. It would have been a perfect move if she'd pressed her advantage, but instead the girl moved back and allowed him to recover.

Riven cursed even as he smirked. Celeste wasn't one to be underestimated. At least, not when she was riled. He ignored the tiny voice in the back of his head (which sounded a little like Musa) that compared her to a younger him – both so full of rage and dangerous when unleashed.

The spar lasted a little while longer, Riven landing some hits that even made him wince in sympathy, and the girl catching another lucky shot along his ribs. "Alright, alright, stop!" Riven held up his hand and watched, surprised, as the girl froze in place, bokken still overhead, ready for a strike.

That is some impressive control.

"We're done for now; you can put your sword down."

Nothing. Just a wary stare and an even tighter grip.

Riven growled and tried again, dropping his own weapon. "I said stop, we're done!"

The girl blinked and brought her bokken down to parade rest.

"Alright, so you're not a total loss," Riven admitted grudgingly. "You've still got a long way to go, and you need to learn how to attack, not just defend." He paused to see if she would say anything and had to force down a wave of anger when she didn't. "You get the rest of the day off to do your coursework – I'll send you your updated schedule later."

When she didn't move, Riven waved a hand, "You're dismissed."

The girl bowed, put her bokken back on the wall, and left.

Riven looked down at his own weapon and sighed. "That was interesting.

Outside, Celeste was thinking the same thing.

At first, all Celeste could see were shadows. Shadows of trees, shadows of grass, shadows of a river that once wound freely through the forest, now frozen in time. Her hands (but not her hands) came into view holding a rusted key.

Her mouth twitched into a pleased smile – all sharp edges and subtle warnings. It wasn't a nice smile (it wasn't her smile)

A voice too deep to possibly belong to her spoke. "Finally."

Author Notes

Hi everyone! Here lies the updated, hopefully better version of my previous Winx fic, Celestial Winds! To those who read CW, thank you for taking a chance on this one! To my new fans, welcome!

This WILL NOT BE RIVENXCELESTE. There will be a brother/sister relationship between them. MusaxRiven is endgame!

Kudos to those who notice my little nods to other fandoms ^u^ and come scream at me on Tumblr Celebrimbor97.

This will hopefully be updated every week or two, so see you soon!