A hero of justice [My hero academia x Shirou Emiya]

Trace On...

I am the bone of my sword
These simple words changed everything.
His quirk had awakened far beyond its limits, a power previously unknown to mankind.

And thus he woke up. Finding himself in the guest room within Buckingham. He places his hand on his face and wonders, was that a dream? Is this power now truly his?
A rush of pain invades his body as his lungs began to shrink. They were unnaturally big before to accommodate gradation air. But now his weapons are formed with willpower alone!

TRACE ON

Reaching out his hand begins materializing a weapon. A sword from within his domain comes forth. As blue lines appear on his body branching out all across his arm like a giant tree it finally materializes. Colada one of the swords of El Cid Campeador. A weapon that's described as making those who are unworthy run in fear.
It's a beautiful long sword, having no impurities and a curved hilt.

Holding this sword. Memory's pass through his mind, not his but rather the sword skill of a legendary warrior, the champion of Spain and a great protector of his people.

"Are you awake yet brother?" Momo knocks on his door. She always woke up later, but it seems today that Shirou needed a long sleep.
Getting up and throwing some clothes on he opens his door to be met with Momo and Artoria waiting for him. "Good morning!" He says to both of them to which they both smile. "Come down, Mum and dad are waiting!" Momo begins to run downstairs Artoria being competitive decides that this is a race.

"Race you!" Artoria runs off using her superior bodily strength to soon catch up with Momo who begins to create something in an attempt to pull ahead. Shirou only now knowing what's going on tenses his body and activates a part of his quirk.

Reinforcement

increasing his bodily strength he is now able to catch up with them. As their dash through the halls is about to reach the front room, Momo finally activates her quirk

Creation!

A purple diagram appears in the air next to Momo, it glows a bright purple as it quickly comes into existence. A jet pack. Putting on her back she rockets forward flying into the front room first soon followed by Artoria who barely beat out Shirou by an inch.

"Victory!" Momo shouts looking back at the two losers behind her. Artoria is annoyed by this fact. "I challenge you to a duel Momo!"
She attempts to get her honour back by challenging Momo to a duel of swords.
This shocks the parents who were just peacefully talking.
"Fine, I will accept your challenge. If Shirou has to fight two!"
This is momos trick, she can't beat Artoria one on one. As Caliburn will cut through anything she makes. But if she can distract her by using Shirou as a body shield she could get a good shot off.

"Fine! I accept your terms, come Momo and shirou to the combat room!"
The parents begin to walk to the combat room hoping to see which one of their Daughter's are stronger instantly assuming that Shirou would lose.

When they entered the battle area one of the butlers was already standing in the middle taking the role of referee.
All three children stood around the area waiting for it to begin.
The referee began listing the rules.
"No murderous attacks, no attacking opponents when they are unconscious or surrendered, no attacking the referee and no teaming up to fight one opponent.
"Understood?" The referee waited for confirmation that they wouldn't break the rules.
"Got it!" All three kids shouted
"I'll count you down then."

"3" Momo began producing swords floating above her
"2" Caliburn was summoned by Artoria who pointed it at Momo
"1" Shirou began searching for a good blade to win this

"Begin!"
Immediately artoria rushed Momo looking for revenge after her earlier loss. Momo fires off her swords, a few firing every second, the majority of them heading towards Artoria who promptly cut anything approaching in two. But Shirou received a few attacks as well. Hoping to defeat him quickly so Momo could use him as a body shield.

Trace On!

A beautiful sword once one of the 13 treasures of the island of Britain. Dyrnwyn the White-Hilt
Engraved upon its blade is a single phrase
"When a worthy man wields this blade it shall burn his enemy's away."

Appearing in his hand he swings it destroying the two swords that flew in right front of him. At this point, the sword should be set on fire giving it great power. But nothing happened, it seems that Shirou's weapons are made of will. He can't activate its noble Phantasm unless he has a real reason to fight. Something he severely lacks due to this just being nought but a spar.

Everyone apart from Shirou himself was shocked at the fact that his weapon didn't snap or look damaged from the attack. Momo herself was so confused that she stopped looking at Artoria. That was her mistake as she was punished brutally with a hit to the stomach as the flat end of Caliburn sent her flying out of the arena.

"Haha, honour restored!"
Artoria shouted looking at Momo who'd been flung out of the arena with enough force that she had to be stopped by the butler. Or she'd be a permanent attraction implanted in the wall. Artoria causally turned around ready for what she believed would be an easy fight.
She was wrong.

Shirou immediately closed in on her and swung at her head. She barely manages to block it with Caliburn but Shirou doesn't slow down.
Trace on!
A nameless weapon appears in his left hand threatening to cut her in Twain. She jumps back barely escaping his melee range, as she is just coming to terms with what happened she has to panicky defend against two swords being thrown at her. Shirou quickly begins his move again activating his quirk and summoning colada holding it with both of his hands he rapidly approaches his target.

The weapon Colada has a very interesting rule intrinsic to the blade. "If the opponent doesn't abide by the rules of chivalry they aren't worthy to face Colada." And without realizing it Artoria had broken these rules with her challenge to Momo. She wielded Caliburn, a powerful noble Phantasm, yet she accepted a challenge that involved someone she believed to have nothing of that calibre.

And such the rules have been broken!
A rush of fear flows through Artorias body as the Coladas effect took hold. It made her want to run for the hills and never return. She could barely hold her sword at this point. She nearly gave up but something woke her up. a spirit that wasn't her flowed through her body still prevalent with her sword.

"Fight"

"FIGHT"

An endless wave of golden light erupted from her blade burning everything around her. She smiled happily at Shirou who was still approaching despite the heat radiating off his opponent.

"My God, what is this?" Shouted the father of the yaryorozu's
"It's beautiful..." said the current king of Britain
The mothers were shocked into silence

Raising the sword above her head she looked towards Shirou who was beginning to trace a new weapon hoping to stop her.
"You truly are worthy to be my scabbard Shirou..."
"Trace On!"
Not a weapon but a sword style. A samurai sword created by Shirou to be "the fastest" is a last-minute improvisation done when faced with an impossible force.

"I shall become a king above all others!"

"I shall outrun the shadow"

"Sword of Selection, grant me power!"

"To cut through the light"

"Caliburn!"

"Iaijutsu!"

Shirou moved forwards in a flash his sword about to meet Momo's neck! But he wasn't fast enough...
The holy sword was swung downwards cleaving him in burning golden light. He was flung out of the area in an instant and he began to fall unconscious. As he fell into sleep he saw his sister and Artoria who looked happy that she had won running towards him going to check if he was ok.

He wasn't... his entire body was covered in bad burns. Luckily they had begun to heal because of Avalon. But it still hurt like hell all across his body.

"It hurts..."
He whispers out as his eyes shut
"It's ok my scabbard."
And before he even had a chance to think about what the hell she was on about he fell unconscious.