This is second prologus or sort... I usually update three consecutive chap for my new story to give better idea what to expect from them.

The Sky's Trial

Cruelty

Then the image shifted to a gunfight, smell of blood and smoke hung in the air heavily.

Betrayal…

This time someone slit my throat, it was a swift death.

Revenge!

Burning buildings and human… smell of burning flesh…

"My eyeeeeeeeeee!"

"Please! Spare my son!"

"It's so painful! Stop!"

This was the sin of Vongola.
Their curse and blessing.
The legacy.

Looking back, his rebirth in from the grail's accursed fire was in his blood. As Vongola's history could be summarized as sacrifice, sin and blood. It was like a match in heaven with the corrupted grail, another startling revelation as memory of his ancestors came rushing to him. The trial of inheritance was alike to what he had been through when Angra Mainyu tried to consume him.

It was no 'all evil in the world' but accumulating sin for ten generation was close enough to that, and it was sickening to think from generation to generation all Vongola had to shoulder sin that was not theirs and live to pass it on their children.

"If you desire power, accept it!"

"This is the trial of our family."

"A tainted one like you…"

"Accept our burden!"

Shirou looked up and found figures from the past with mask of flame chanting demands, one after another. Imagining young and vulnerable boy going through this like him made the counter guardian's blood to boil.

"Accept?" He echoed their demand, "I have walked the path of Ashura!" He roared at them, "I killed hundreds to save thousands! I understand why you do what you did! However…" He trailed off with a growl, "I will never accept it! NEVER!"

"Who are you to preach justice?"

"Justice is not fairness."

"Neither it's kindness."

"You're bloodied, just like us."

"And you're right!" Shirou replied, "You're right my hands are as dirty as yours! Unlike Tsunayoshi who came to this trial, still pure.. I have no right to think I am above you! But I have right to say that… never once in my pursuit to be a hero I accept my sins as anything else but wrong! I regret even if it's out of my control!"

"Pathetic."

"How sad…"

It had been a while he got angry at someone for legitimate reason, so he did. "You guys are even more pathetic than I am!" He pointed at them indignantly, "Ten, no… nine generations and you repeatedly doing the same mistakes! And the this stupid trial?! You want to make me to accept your sins and repeat it again?! You want me to accept it's okay to fall to the same hell hole?!"

"..."

He shut them up? Finally! "I did all that already, but at least I'm willing to admit the mistake is all mine! And I am not going to drag anyone, much less my descendants to accept it!"

That was right, his quest to kill himself while selfish also boiled down to his desire to 'save' someone from their suffering. He was not going to drag anyone to hell like these ancestors of his. "They should do better than I did, and I swear here and now! Even if you guys will never accept me, I will do better than you! I will help Tsunayoshi to reach our ideal, and walk on that thorny path without regret!"

He was panting now, on his knees but he refused to fall any further. His mental strength was sapped dry from everything. He thought he would be fine, he had been through the same thing courtesy of Angra Mainyu but apparently he was overestimating himself. How did he survive this kind of trial alive back then again?!

It was only then the archer realized the world was no longer pitch black and color returned, sky washing over the darkness. Someone's strong hand pulled him to stand and he was greeted by a smile of an old man dressed in grey suit. This man reminded Shirou faintly of Kiritsugu's friend, Fujimura Raiga but also different… a kind grandfather, his mind supplied.

"Aah… it's you." The old man called with kind but also sad smile. "I am sorry, you have to go through that."

"Who… are you?" He asked and a memory flashed on his mind, of a blond woman with amber eyes and her red haired husband begging to younger version of the man before him. The mother was holding a boy around three years old, red hair and amber eyes.
And then, this man told them about Fuyuki, a town out of reach of three great families because of the distortion and corruption. The only place where their divine ancestor couldn't monitor them, and the only place where their son would be free.

This man was their grandfather. "I am Timoteo, the ninth Vongola." He introduced softly before he stepped back and fall in row. "Welcome to the Throne of Sky."

That was then Shirou realized the ancestors, nine of them had formed two rows with the last sitting in a throne made of onyx. The man discarded his flame mask, revealing Tsunayoshi's face but older with blond hair, amber eyes and wearing crown made of flame.

"Your sky is tainted, and the ground your feet standing on is filled with blades." The golden haired man said, "Even so, that's a honest expression of your world… that you do acknowledge your mistakes as yours alone and you didn't regret it, no longer…" He murmured softly but it rang in Shirou's ears all the same.

This man was Primo, the first to shoulder the burden of Vongola family.

He was smiling now, the same smile Tsunayoshi gave Shirou. "How strange… you have been betrayed, broken apart but in the end you stays true to your ideal. You're so human but in the same time you're also the closest to Tsunayoshi and I."

What did he mean by that?

"Your resolution too… similar to Tsunayoshi but not the same, I am very fortunate with this generation indeed." He raised his hand and chanted, "Our time engraved within the ring… I accept your resolution, Wrought Iron Hero… EMIYA. To prosper or to ruin, it shall be in your hand."

Shirou gasped as mark of Vongola lit up beneath him and enveloped him in golden flame. "And so you shall be granted a mark, the crest of Vongola!"

And his world was set aflame.

The Journey

The first thing Shirou noticed when he woke up was something felt really off with his body. When he was deployed, his copy was given a perfect vessel that felt the same as his living body. However this body felt… fake, and when he ran structural analysis on his body his senses couldn't tell it apart with the real one. This body was made of pure prana but in the same time very real, a realistic illusion.

Second thing he noticed, Tsuna was sitting beside his bed and was in the middle of cutting apple to bunny shape.

And third, the bedroom he was sleeping in looked like it was made for a king.

"I'd put you in Japanese style room, but Mukuro said considering your condition we should put you in room with solid wall." Tsunayoshi informed him, before popping a slice to his mouth. "And also, can you call me Tsuna?"

Shirou blinked owlishly at him, "Erm, I can't complain what kind of room you get for me." Even though Tsuna was right, it was too lavish for his taste. "Tsuna, I think the explanation should start from what's with this… real but not quite body I have now. Is this some sort of 'Gradation Air' or 'Projection'?"

"Hum…it's power of Mist Flame, the property is construction." Tsunayoshi explained, "It creates something from nothing but it's no denial of nothingness, basically it's a flame that deceive Gaia that the constructed material is real."

In short his body was an illusion, not just to him but also to the world. "Is your power all about skirting around the realm of true magic?" Shirou couldn't help but wondered. "Then again you're related to me by blood, and I suppose after those headaches I gave my friend." Namely Rin."With just being me, I suppose it's a fair deal."

Tsuna just nodded and Shirou wondered if his cousin just agreed with him that he deserved this.

Eyeing the neatly cut bunny apple Shirou asked, "By the way, this body can eat right?"

Tsuna paused at that, before nodding. "Ah yes, you can."

"What's with that pause?"

"I am not sure your body can works like a real one to that degree, but since Chrome's illusionary organ works I suppose there would be no problem."

Shirou nodded at that before taking a piece of offered fruit, "By the way, who are Mukuro and Chrome you were referring to?"

Tsuna smiled, "They're my mist guardians…"

Guardians of Sky, six individuals named after weather phenomena chosen to support the sky. The pillars of support that make the sky complete.

"...I see…" The fruit tasted a little plain to his tongue, but it was expected with this body. "And also my soul… this is not a copy, embodiment of my ideal but my real self." It was strange to feel alive again.

"..."

"I still have to pay the price though."

Tsunayoshi took a deep breath, "To be frank I am amazed of your stupidity to sign that contract without thinking it through, but then again if we're that smart our ancestor won't sign himself up to this position in the first place."

"..."

"...Sadly the world needs idiots like us." Tsunayoshi concluded, peeling another fruit, this time a mandarin.

Shirou chuckled softly at that, "Right… so when I can start working?"

"Shirou." Tsuna intoned, "You have been working for how long again? Would it kill you to wait?"

Back to his old routine again, forgetting his limits. "Right, but may I know what I have to do first aside from… laying down?"

Tsuna smirked at that, "Well, we will see your flame first."

"My flame?" As incarnation, he couldn't use elemental magic, right?

Two Days Later…

It took that long for Shirou to be stabilized and in sync with his new body to start anything. So he was pretty excited when he was asked to go to training room, it was nothing like a dojo but a plain room with steel like wall on all sides. Considering he was going to try using his 'Dying Will Flame' the choice of room made sense.

Still… manifesting your life force as flame, it sounded like a simple enough branch of magecraft in Shiro's opinion. He tried as they instructed and succeed relatively quick, but judging from disappointed look on Mukuro's face it was not the case.

"Soft Sky Flame…" Mukuro remarked, "You went through all that but the purity of your flame is really poor."

Tsuna nodded, "Actually all thing considered, with that polluted sky in your inner world this rate of purity is already decent. You have will power in spades at least."

The flame was very pale, gold with a hint of white. Shirou wondered if he didn't reaffirm his ideal he won't even be able to accomplish this much. "There's no way to purify myself, is there?"

"I wouldn't know, I never have this problem..." Tsuna admitted, "But with this much purity and density your flame would be limited to propelling property."

"Not to mention…" Mukuro interrupted them, "Can he even fly properly with this? Lack of power aside, he would have a hard time adjusting flame output."

His eyes widened in shock, "I can fly?" He could jump really high but flying was beyond him.

Mukuro face-palmed, "Why do you think Vongola bloodline called The Sky Children? It's a literal title."

Shirou sighed, "Right… I don't think so, unless…" He projected a nameless sword, a mystic codes which properties was just channelling element to certain extent. He altered the sword to be broader to the size of his largest broadsword and channeled his flame.

"Huh, don't tell me-"

Shirou did as Tsuna expected, he hopped on top of the sword and the weapon started to float above the ground slowly. "It works well…"

Tsuna couldn't believe this. "Is sword your answer for everything?"

"I am sword incarnation, and I have good experience in solving problem with anything remotely pointy and sharp." Emiya Shirou informed his cousin with no small amount of smugness.

The sky took a deep breath, "I can see that, so I suppose you're good keeping yourself alive?"

"...At almost getting killed but I get better."

"...I guess so, but try to survive for the next few weeks."

"What do you mean?"

"Well, Kawahira asked the Arcobaleno to assess you and let's say…" Tsuna trailed off with a sigh, "They're all very unhappy with you because that man spoke to them because of you."

"Huh?"

Shirou thought he already knew hell but apparently, there's a new version of hell and it's in rainbow color. Especially Reborn who introduced himself as Tsuna's tutor, he would put even strongest servants to shame. The pragmatic hitman was so alike with his adopted father it was not funny. Seriously, who thought it was a good idea to magnetize his armor and since Shirou's main weapon was bladed weapon…

The result was not pretty.

"You're an interesting one-trick pony, Shirou… truly! Especially since your swords are all interesting trinkets, unfortunately they're all made of metal, no?"

Not to mention none of them -aside from one that couldn't die but Shirou was not counting the octopus punk- even give him a chance to chant. The illusionist even paranoid enough to turn the room to underwater ground beforehand. The scientist was just watching but he creeped Shirou out.

"No veteran would be idiot enough to let you finish chanting."

It was terrifying revelation that five out of six, they were trained to kill Magus, they didn't hold title of Magus killer but they were all know how to kill Magus inside out.

"And also, just because you have weak flame doesn't mean it gives you an excuse to use it as glorified rocket. You got one tiny drop of potential in Magecraft and perfect it before, do the same with your flame. A Vongola without flame is a tragedy!"

And this was not even training, at least Shirou didn't think it was one. More like they point him to one direction to go and then kicked his ass so hard to the deepest pit so he could climb up.

"Cousin, you're still conscious?"

Emiya Shirou was so glad his cousin didn't take after Reborn, no wakeup call with gun. Magus could talk about walking with death, but in here… more like death is hanging around your shoulder all the time, like an annoying friend you couldn't get rid of.

"I am already dead, technically… why they're trying to kill me again?"

"They're assessing you."

"I don't know, how beating me up to the verge of death tells them anything other than how suck I am?" He had plenty of experience fighting monster and servants, but quasi combination of monster and Magus Killer? Nope, they were completely different hybrid altogether.

Tsuna had one-hundred-yard stare in response, "Well, if Magus walks with death… we're running lap around it. Traditionally awakening your flame at young age takes conditioning to death like state, hence the name Dying Will Flame…"

"…That's more like shaking hands with death."

If Rin could see him now, that girl would never let him to live this down.

Shirou suddenly remembered, "I have seen all Vongola guardians, and also Arcobaleno holders." Tsuna's family was eccentric and at first meeting wary of him. Especially the cloud and rain, they just froze and seemed unable to decide what to do in his presence.

It had something to do with his 'polluted' sky, and from what he could see it would take some time for them to be comfortable around him. Which was a pity, Yamamoto had a very interesting sword.

"But I haven't seen the Sky Arcobaleno or any Mare holders yet."

Tsuna sighed at that, "Ah yes, at least for formality sake I should let you to meet them. However, Aria-san is still recovering from her illness… and Millefiore family lives in America. I'd rather you to not see Byakuran anytime soon."

"Is he another Zelretch?"

"Well… he has similar sense of humor and pretty loopy because of his power." He shook his head. "Anyway…"

Shirou pretended he didn't notice the abrupt change of topic.

Tsuna turned to him, "That body wouldn't last anymore… but it serves its purpose."

He nodded, he knew from the start the illusionary body was temporary.

"You have cut off your own escape route with that contract, Shirou." Tsuna's eyes looked straight at his, which now had returned to vivid shade of amber like Tsuna. "What we're about to do is fulfilling our duties, and you… you will suffer more than anyone else. You would be there to see how merciless fate is as the past has been set in stone, and there's not much loophole you can use."

At worst case scenario, there was nothing to save.

Shirou nodded, "I knew that very well, Tsuna… but I have no regrets. I am a fool who strive for an ideal after all."

The sky exhaled, it was already too late to turn their back. "Very well, then we can start."

"Loop of Fate Project."

Unknown Timeline and Location…

[Silver and iron to the origin. Gem and the archduke of contracts to the cornerstone. The ancestor is my great master Schweinorg.
The alighted wind becomes a wall. The gates in the four directions close,
coming from the crown, the three-forked road that leads to the kingdom circulate.
Shut (fill). Shut (fill). Shut (fill). Shut (fill). Shut (fill).
Repeat every five times.
Simply, shatter once filled.
――――I announce.
Your self is under me, my fate(doom) is in your sword.
In accordance with the approach of the Holy Grail, if you abide by this feeling, this reason, then answer.
Here is my oath. I am the one who becomes all the good of the world of the dead,
I am the one who lays out all the evil of the world of the dead.
You, seven heavens clad in three words of power, arrive from the ring of deterrence,
O keeper of the balance ―――！]

The master gasped as the man shrouded in red with gold rimming, black armor appeared before them. Skin dark but hair as white as snow, and when his eyes opened it as if they were embedded with amber stones.

"Servant Ruler, I have come forward to answer your call.
I ask of you, are you my master?"

I will fix the prologue sooner or later… proof that my line of thought is as choppy as my writing.
As you can see Shirou went through a week of Spartan tutor, but well they just give him pointers. I have a hard time determining how strong Arcobaleno in Nasu-verse and I settle on level of Apostle ancestor for some like Reborn and Fon.

Before anyone point it out, yeah… I know Ruler usually have no master, but I am sure you guys have an idea who could be his master and why it would make sense. Yes, I know Emiya is no saint but well… ideal wise, he is ONE.

Next I will rant on my dashed enjoyment from watching Zero to UBW…

UBW from what I heard in forum gains good review for graphic, in short it's a very beautiful anime but plot wise… a let down to some. I also feels that way, but I will blame not the animation studio, Kinoko Nasu or Urobuchi. It's just Fate/Zero comes first and blow our mind away with complex storytelling and features Saber as idealistic King who in spite of trying her best failed in her duty. She and Kiritsugu are perhaps the worst partners to each other, but their characterization is just AMAZING.

To be honest I think after Fate/Zero they should remake Fate route first… nothing to do with my preference but it's more logical to shift from Fate/Zero Saber to Fate route Saber, because the highlight of Fate/Zero's end is Saber's vow to win the grail at all cost. Then in UBW she becomes side-chara, which is fine but then there's no 'desperation' from her previous characterization in Zero carried over to UBW.

If I didn't watch FSN first anime first I would be very confused too and feeling the discrepancies at its worst. I think the staff makes UBW notice this too and quickly draw a good parallel between Archer and Saber, both used to be idealistic and fall from that ideal in the worst way possible in their life, regretting and wish to somehow 'correct' their past. Unfortunately by then UBW only highlight Saber's loyalty to Shirou as her most defining trait, the 'crack' in her person from Zero dismissed. I get the focus shift to Shirou and Archer but I feel Saber's desire for the grail drop to Rider's level, as in my master come first, the grail is not that important.

So yeah, for those who gets disappointed by UBW Saber... that's what happen I think.