Now, I know a lot of you are excited for King of His Heart, and that's still in progress, with four chapters down. But...well, this idea grabbed me and wouldn't let go. Dis Lexic gave me permission to post my own challenge, 'A Second Chance for Mordred', which was similar to their 'Awaken the Dragon' challenge, but with Mordred substituted for Arturia. That's more of the background to this story, which also uses my 'Taiga! Taiga!' challenge as a basis. I actually considered doing that challenge as a Harry/Sakura story, before Hadrian Kotomine became more enticing at the time.

Basically, this is a modified version of Fate/Stay Night: Unlimited Blade Works with Taiga aware of magic and being Harry's guardian, as well as Harry and Mordred being thrown in. Now, keep in mind, Harry won't be summoning up a Servant. Of course, just because he won't summon a Servant doesn't mean he won't get involved...or that he won't get one later on.

There's no guarantee that this will get posted as a full story...but it may. Hopefully, you'll enjoy it anyway...

KNIGHT OF BETRAYAL AND TAIGA CUB

CHAPTER 1:

A CAMELOT KNIGHT IN FUYUKI CITY

He hated it. All the questions and pestering. He wasn't sure what was worst: the cold amorality of the Magi, or the sheeple mentality of wizards. At least Rin and Sakura, he could speak to, not to mention Shirou. He was thankful he could get a Portkey back to Japan, and even more grateful to his…well, he had thought of her as his mother for many years, even though she was only nine years his senior. In any case, she was a better guardian than those relatives who died in that fire seven years ago. She even took the fact that he could use magic in her stride, after the initial shock.

Of course, the fact that he was entered into a damned wizarding tournament with a high mortality rate (though not as high as the Grail War, thank Merlin), and even with the danger toned down somewhat, it was meant for bloody students reaching their…NEWTs, as they called the wizarding education for those who reached the end of their school studies. He was caught between Magus and wizard. Wizards could use magic more readily and without gaining the attention of Gaia, most of the time, while Magi's magic was considerably more versatile but harder to use. He could use both, though he favoured the magic of wizards rather than magecraft of the Magi.

The attitudes of the two were equally different. While both Magi and wizards were conservative, wizards tended to be complacent and indolent, even stagnant. Magi, by comparison, were more amoral, and tended to take a more scientific approach to magic. Where most wizards might balk at human experimentation, many Magi would do so on the quiet. He had to be grateful that the only Magi he knew weren't anything like that. Then again, his knowledge was restricted to three teenagers about his age, and that damned vampire Zelretch, who had been the one to notify him about the Tri-Wizard Tournament. About how he was under a geas on his original name.

Anyway, he'd been wandering the corridors of Hogwarts later that night, unable to get to sleep. That was partly due to jetlag…well, Portkey-lag. Then, there was the Tri-Wizard Tournament and its dangers. And, of course, there was being separated from his mother. He intended to stay only for a short period here, up until the end of the First Task. He'd head back to Japan then, and commute between Japan and Britain for the other Tasks.

In any case, Zelretch had given him an intriguing bit of advice…or whatever passed for advice in the infamously trolling vampire. He said to seek out the Room of Requirement, and have it come into being by thinking, I seek whatever Merlin left in Hogwarts. Zelretch had hinted that there was something there that would help him survive the Tri-Wizard Tournament.

Maybe it would be a Mystic Code left behind by Merlin, or even a Noble Phantasm. He hoped so. Even if he didn't need something as overpowered as a Noble Phantasm, it would be great to have.

He found where Zelretch had claimed the Room of Requirement would be, and paced in front of the wall near that damned painting of trolls being taught to dance, thinking I seek whatever Merlin left in Hogwarts. On the third time he passed in front of it…the wall changed, a door appearing. He went over gingerly, and opened it.

The room wasn't what he was expecting. Instead of an arsenal of weapons and magical artifacts, there was a bier, on which a body was lying. An armoured body, clutching a sword. As he walked over, he saw that the person was wearing an intimidating horned helmet. The whole outfit was red where it wasn't metallic. Their hands were crossed over a sword. He resisted the temptation to take it, though, at least until he was sure he could take it without setting off a boobytrap. Plus, as much as Magi tended to be amoral, he felt a bit uneasy about tomb-raiding, which this felt like.

A letter was on a lectern nearby. Oddly enough, it was addressed to him. And yet, the letter itself look ancient. He opened it up, and frowned. After it had his name, it went like this…

Greetings from the past. The thing about precognition is that it's rather unreliable, especially when one gets far enough into the future. Still, one thing I did see would be your arrival here in this room. I saw your character, and I feel that you are the right person.

You see, the one laying in state in front of your very eyes is one who had a bad lot in life. I believe you may be what they needed, not what they sought. They were said to have died at Camlann, no doubt, but I left instructions with my followers to rescue them.

You both will be good for each other, I believe. During their time here, they have been kept in stasis while their wounds were healed, fuelled by the leylines of Hogwarts. They can teach you how to survive, and you can teach them how to live.

Anyway, best of luck.

Merlin Ambrosius, Magus of Flowers

He frowned. Was this all some sort of prank Zelretch had set up? Surely Merlin would not have addressed an envelope to him personally?

Suddenly, there was a gasp from the armoured figure on the bier, and they sat upright. Their helmeted head swivelled around to look at him, and there was a snarl of anger. The figure tried to leap off the bier, only to tumble to the floor in a loud clatter. He was uncertain of what to do at first, but then went over to them, and helped them to their feet. The figure looked at them, and seemed torn between being angry and grateful. "Are you all right?" he asked.

"…I'm not sure," the figure said, their voice gruff and rough…and yet being oddly high-pitched for what he expected. "In fact…I didn't expect to wake up." They gently touched his robes. "…Your clothes are weird…where are we?"

"Hogwarts, Scotland."

"Hogwarts? That school founded by those wizards?" The figure then peered at what was on his wrist. "What is that?"

"It's a watch. It tells you what time it is."

"…Can't you use a spell or something? I've never seen anything like it."

"…Well, it's probably been a long time since you've been asleep. I got this letter from, well, Merlin, of all people, and he's been dead or gone for over a thousand years…"

The knight whirled to face him. "Merlin?!" they hissed. "…Wait, did you say dead or gone for over a thousand…years…?"

"…Yeah. I'm…sorry. Look, I know this might be a bit of a shock, but…who are you, anyway?"

"You first," the knight said.

"Uhh, all right. I am Harry Fujimura, though I was born Harry Potter."

The knight seemed to absorb this, before nodding. "…Well then, Harry Fujimura, I shall introduce myself." They straightened, and suddenly, their helmet seemed to disassemble itself, folding up and sliding in pieces down the front and back of their armour. And when Harry saw the face beneath, he couldn't help but stare.

The face was androgynous, but he realised she was a girl about his age, with a beauty that seemed somewhat wild, untamed. Her beautiful emerald eyes were much like his own, and her messy golden hair was tied back in a ponytail.

"I am Mordred, rightful heir of Arthur Pendragon, King of the Britons!" she declared proudly.

"RAAAGH!"

The roar of Mordred Pendragon as she lunged at Harry with a shinai was a by-now familiar sound in the Fujimura household. And to tell the truth, despite the cacophony, it was a welcome one. Mordred, who went by the name of Artemis Fujimura or 'Art' in public, loved these almost daily sparring sessions, either with Harry or his adoptive mother, Taiga (and he was one of the few people who could call her 'Tiger', albeit not without complaint). Mordred was no kendoka, but she was a brilliant swordfighter forged in the strife-filled times of Arthurian Britain, even if she fought dirty.

And to tell the truth, both Harry and Taiga did too. Taiga had been something of a champion kendoka until she got disqualified from an international kendo competition for, according to her, 'being too amazing at owning bitches(1)'. She taught Harry everything she knew. And Harry was one of the star players at the local high school, Homurahara. Mordred would be better at swordplay, but she was disqualified at her first kendo match for using too many illegal moves, much to her anger.

Of course, there was a difference between kendo, or indeed any kind of fencing, and the swordplay one saw on the battlefield. Mordred had fought in many battles back in Arthurian times, after all. But Harry found her style of fighting refreshing, and he used something similar whenever he sparred with her.

Their friendship, indeed, their love got off to a rocky start. Harry was confused at the fact that Mordred was a girl, and had nearly been attacked for his troubles, given Mordred's issues with her gender. There was also the uneasy feeling he had, being around the infamous Knight of Treachery. It took much of the following couple of months for them to get used to each other, but their friendship had, surprisingly, become strong by the time Christmas of that year rolled around, and he needed a date to the Yule Ball. It took some persuading for Mordred to accept that…though that was mostly because she refused to wear a dress. Oddly enough, a tuxedo was more to her liking, once she was told she had to cover most of her skin.

By the time the Tri-Wizard Tournament ended, and Harry managed to escape from that graveyard (though not before managing a sneak attack on Voldemort while he was monologuing, managing to kill that current body), Harry and Mordred had become firm friends. In truth, he made few in Britain. That Hermione girl, that dotty little blonde Luna, the Weasley Twins and their younger brother…and that was pretty much it. Oh, he now had some family in the form of Sirius Black and Remus Lupin, both of whom were now staying at Clock Tower under the protection of Zelretch, due to Sirius being framed, as well as Sirius' relative 'Don't Call Me Nymphadora' Tonks, who was now working for the Enforcers at Clock Tower. Then again, it wasn't like he had many friends here. Aside from the three young Magi, he could count Issei Ryuudou as a friend, and that was it.

Harry was broken from his musings, and thus being distracted, when he his guard was knocked aside by Mordred, who knocked him to the ground. "Hey, quit your woolgathering, Harry!" she snapped. "I want a decent bout, not a curbstomping!"

"Sorry, Mordred," Harry said, getting up. "I was just thinking about when we first met, and how it could've been worse."

"Whaddya mean?"

"Like when Shinji made the mistake of hitting on you, and when you refused, he said you were too mannish, despite the fact you didn't have the equipment."

Mordred laughed. "And I told that blue-haired prick I would remove his equipment…if I could find a blade small enough. Seriously…had to give him some percussive maintenance to get him to keep his hands off Sakura, especially when she and the idiot started dating."

"Mordred, Shirou's not an idiot. He's just…singleminded."

"That's one way of putting it. Seriously, he didn't know how to use his magic circuits properly until you and Sakura got him to get his act together. I wanna exhume that idiot of a father of his and bugger him with Blood Clarent Arthur for teaching him to do it that way."

Taiga, who'd been looking on, scowled, crossing her arms. The ditzy woman with light brown hair cut short was actually in a relationship with Remus Lupin, and didn't care that he was a werewolf. Lupin was currently working at Clock Tower with Zelretch to try and gain Sirius' freedom. "Mordred, the Kiritsugu I knew was a good man. I don't care what Rin or those weirdoes in Clock Tower claim. So you won't be doing any buggery of Kiritsugu's corpse, with your sword or otherwise!" She closed her eyes and sighed. "That being said, I hope what's been happening lately isn't a sign of things to come. All those murders, gas leaks…that doesn't sound good. We had all those killings ten years ago by that nutjob."

"Yeah, Rin mentioned him," Harry said. "The Master of Caster. They later identified him as Ryuunosuke Uryu."

"Well, that was a scary time, and I didn't even know half of that stuff was caused by Magi doing their thing for a magical cup," Taiga said. "I didn't even realise that shrimp Waver was one, and that big burly guy was Alexander the Great! I would've asked him for an autograph, otherwise. I hope it's not happening again."

"If it is, it's way too soon. It's meant to happen every sixty years, not ten. And Zelretch hasn't said anything yet. Neither has Waver. Then again, Zelretch would probably not tell me just for shits and giggles, and Waver's probably busy. If there is a Grail War, Rin's sure to be a Master, given that she's the only Tohsaka…unless the Grail decides it would be funny to choose Sakura as a Tohsaka Master rather than a Matou."

"Nothing funny about this," Taiga said with a scowl. "Anyway, we'd better have a shower before we head over to Shirou's for dinner…"

Mordred's identity was actually a secret, even to Harry's friends here, save for Sakura. Oh, Shirou and Rin knew that 'Art' was not her real name, and that she was more than what she seemed, but made up their own conclusions. Rin guessed correctly (albeit for the wrong reasons) that 'Art' was a Homunculus Harry had obtained in Britain. Shirou had an impression that 'Art' was part of some secret knightly order.

Sakura, however, had learned of Mordred's identity when Mordred spoke to her, having the closest thing the tomboyish knight could have to girl talk. It was after the incident with Shinji, and Harry was concerned for Sakura. They'd even learned about her Uncle Kariya being the Master of Berserker, who apparently may very well have been Sir Lancelot, of all people. Mordred may not have had as shitty a childhood as Sakura (and they were yet to realise how shitty it really was), but she could be there for the shy, introverted girl.

Harry, Mordred and Taiga used Apparition, courtesy of Harry, to get most of the way there, with a Bounded Field set up by Kiritsugu preventing Apparition directly into the Emiya Household. They appeared with a muted whipcrack-like noise, just in time for them to be in an alleyway near Shirou, who leapt into the air at the noise. "Whoa!" he yelped, hurrying over. "Hey, you guys…you scared me!"

"Sorry, Shirou," Harry said, as he and his mother, along with Mordred, hurried over and joined him.

"So, what's on the menu tonight?" Mordred asked.

"I think Sakura's already made a start on it," Shirou said. "Seriously, though, I dunno how you can pack away that much."

"And as I keep telling you, I got my metabolism from my father," Mordred said. "Anyway, I'm a growing girl."

She was. While she remained relatively understated in the bust area, she had filled out a little more in the years since Harry found her, not to mention growing a little in height. Then again, most of her appetite was due to her oversized magic core: while she couldn't use most magic, she had enough to use for Reinforcement, the Mana Burst, as well as swapping in her sword Blood Clarent Arthur and her armour Secret of Pedigree. She may not have been at the level of a Heroic Spirit, but she could break human limits and approach that level if need be.

They walked down the street in silence, only for the quartet to pause when they saw someone in the road approaching them. To Shirou, Taiga and Mordred, she seemed merely like an oddity. A girl of perhaps 12 at most, dressed in heavy winter clothing, with an ushanka on top. Her hair was as pale as her skin, and her eyes an eerie ruby red. She could have been an albino.

But Harry had this bad feeling. He knew albino looks were the hallmarks of Homunculi created by the von Einzberns. And that smile didn't bode well.

As she passed them, Taiga said, "You know, it's a bit late for a kid your age to be wandering around alone."

The girl seemed nonplussed briefly, before she passed them. She called out from behind them, "You know, big brother, if you don't summon it soon, you'll come to a sticky end."

The four of them whirled, but the girl had somehow vanished. "…That was ominous," Harry said, with considerable understatement.

"What did she mean by that?" Shirou asked.

"…It means, Shirou, that we'll need to make some phone calls when we get to your place," Harry said grimly. "Because we're in very big trouble. The Fifth Holy Grail War has begun…and it seems that the von Einzberns have an axe to grind against you…"

CHAPTER 1 ANNOTATIONS:

So, Mordred and Harry, of all people, are together. We'll be alluding to events that happened earlier in their relationship, with maybe an occasional flashback. However, this version of events will be largely based on the Unlimited Blade Works route, albeit with Shirou shacking up with Sakura rather than Rin, as they already have a relationship going. In fact, the first half of the events will be broadly similar…but once we get to the second half of the series, well, things will start to be derailed.

1. This was based on Taiga's boast in The Bae Cometh, Episode 1 (but not the first episode) of Project Mouthwash's Fate/Stay Night: Unlimited Blade Works Abridged. It sounds exactly like the sort of thing Taiga would say when drunk.