Author's note: I do not own Mobile Suit Gundam 00. Sunrise does.

"Eh? You want me to test out another new mystic code?" Shirou asked Da Vinci as they were in the testing room of Chaldea.

"Yes. And this time, there's nothing wrong with it." Da Vinci replied.

"Are you sure?" Shirou asked with suspicion in his voice.

"Yes! Unlike the prototype mystic code from earlier, this mystic code doesn't have any problems with the construction! I even double checked it!"

"And why do I need to do it?"

Da Vinci had a smug look on her face. "Call it...payback from earlier."

Shirou didn't know what she meant until he realized he has an unpaid debt to Da Vinci from a while ago. He let out a sigh and said, "Well...if you say so..."

"Yes! Now if you'll let me get the mystic code for a moment..." Da Vinci said as she went to a corner of the training room and brought out the mystic code she was talking about. As she returned to where Shirou was, she presented the mystic code to him.

The mystic code itself was a sword, something that Shirou was familiar with. The sword itself was a one-handed sword in which the blade itself was in a transparent green color with some white on the middle of the blade in a design-like shape. The sword's cross guard along with the grip was in a dark grey and it had what it seems to be exhaust ports on the sides. It has a blue-colored knuckle guard.

All and all, it looked like it was made in the future.

"Is this it?" Shirou asked as he was examining the mystic code/sword.

"Yes. Why? You don't like it?" Da Vinci asked.

"It's not that. It's just that...well...the design looks quite similar to something, but I can't remember what it was..." Shirou replied.

"I see. Anyways, try swinging it around a bit."

Shirou complied to Da Vinci's request and started swinging the sword around. As he swung the sword, he thought, "This sword...the more times I keep swinging it and looking at it, the more familiar it gets. But where have I seen this weapon before?"

"Shirou? Are you okay?" Da Vinci said, snapping Shirou out of his thoughts.

"Hm? Oh yeah. Sorry Da Vinci, I was in my thoughts for a moment." Shirou replied.

"I see. Anyways, what are your thoughts and feedback on the mystic code/sword?"

"It's a good mystic code/sword, although I can't help but feel like I've seen this before. The problem is, where though."

"Maybe it's just your imagination."

"You think so?"

"Yeah. Anyways, there's more to this mystic code/sword than this."

"What do you mean by that?"

"Well...do you see a certain grey button on one of the sides of the cross guard?"

Shirou looked at a sword more closely and saw a small switch on one of the sides of the cross guard. "I see it. So what?"

"Well...press it and see..." Da Vinci said with a mischievous grin so creepy it was actually scaring Shirou a bit.

"O-Okay..." Shirou muttered, not wanting to question even further after seeing that smile of hers. As Shirou pressed it, nothing happened.

"Phew. Guess nothing happened then..." Shirou thought as he sighed in relief. Then he was encased in a bright green light. "On second thought, never mind," he thought as sighed again.

As he was trapped in the bright green light, a new voice was heard.

"Registering biometric DNA. User identity known as Emiya Shirou," the object said in a robotic voice.

"Oh boy. Not this again..." Shirou thought as he felt like he was experiencing the first time he touched that prototype mystic code all over again.

"Accessing user's magical circuits and skills. Inputting data from user's history."

Shirou sighed as he knew what was coming.

The transformation sequence.

"Data input complete. Now commencing transforming sequence."

In an instant, the bright green light engulfed Shirou, completely consuming him for a moment. After a few seconds, the bright green light disappeared, revealing Shirou in a completely new costume.

Right now, Shirou was wearing a white helmet with a v-shaped fin with yellow antennas and a red gem-like thing on the forehead. Each side of the helmet has a green clear piece and has a wing-like shape as well. His face was covered by blue-green glass visor glasses and a white face mask with some grey on the side, two mouth vents, and a red chin. He was also wearing blue torso armor that has yellow vents along with a red upper waist, and a white v-shaped piece at the center. His shoulders were covered by red shoulder armor followed up by his arms being covered up in white armor with some blue designed to look like elbows with some clear green pieces in the arm joints, and his leg armor has clear green pieces and some grey on their sides along with some armored shoes with red on the bottom. On the back of his waist was white armor along with two protrusions along with two swords on each side of his waist and the skirt armor was in a v-shape with some red in the middle.

However, the most unique thing about the armor Shirou was wearing was what was on his back. On his back was a blue backpack with an intricate design. One the back was an object that looked like a fighter jet connecting two cones along with two large blue and white binders with a mechanism that allowed them to float without hindering the body as well.

Da Vinci was in awe of how the armor looked. "W-Wow...I think I outdid myself this time..." she thought.

"Um...Da Vinci?" Shirou said, snapping Da Vinci out of her thoughts.

"Hm? Oh, sorry Shirou. I was just amazed at how the armor turned out."

"You aren't the only one," Shirou said as he looked at himself in amazement. "By the way, where did you get the design from?"

"Well...I may have been watching a certain anime..." Da Vinci muttered.

Shirou let out a sigh, "What anime was it?"

Before Da Vinci could answer his question, it was then that Ritsuka and Mashu decided to come into the testing room, looking for Da Vinci.

"Da Vinci? Are you here? We need your help for-" Ritsuka said, but immediately stopped at what he saw in the room.

"Sempai? What's wrong...?" Mashu asked, but slowly stopped her voice after seeing Shirou and Da Vinci in the room.

For a moment, there was silence in the room as nobody said a word. Then Ritsuka broke the silence.

"D-D-D-D-D-Da Vinci, is-is-is-is-is-is-is that..." Ritsuka stammered while pointing his finger at Shirou.

"Yes. The person you're seeing in the armor is Emiya Shirou."

In an instant, Ritsuka immediately went for Shirou and started examining him, confusing Shirou greatly.

"M-Master. Is there something wrong?"

"Are you kidding me? There's nothing wrong right now!" Ritsuka said excitedly as he continued looking at Shirou with sparkles in his eyes. "This design...the colors...the face...the weapons! Everything is perfect here Shirou!"

Shirou was even more confused and looked towards Mashu. "Uh Mashu...why is master acting like this?"

"Shirou-san...the mystic code you're using...it seems like it brought back some childhood memories senpai had."

"Really? What kind of memories?"

"Well...senpai would tell me that right after school would be over, he would head straight home and watch his favorite show. If I remember correctly...the show was called Mobile Suit Gundam 00..."

As Shirou heard that, he immediately mentally face-palmed himself. "So that's why it looked familiar...Mobile Suit Gundam 00...jeez, why did Da Vinci watch that anime earlier?"

"Anyways, is there a problem with it Shirou-san?" Mashu asked.

"Well it's not that...I just hope that Chaldea doesn't get sued by the producers of the show..." Shirou said with a sheepish chuckle.

Da Vinci laughed at what Shirou said. "Relax! They won't know!"

"I hope so..." Shirou thought.

It was then that a notification appeared on Shirou's visor. As he checked what the notification was, it was the technological specs of the mystic code itself.

Name: 00 Raiser

Power Source: 2x GN Drives.

Armaments: 2x GN Beam Saber, 2x GN Sword II, GN Sword III, 8x GN Micro Missiles, GN Beam Machine Gun, GN Vulcan.

Special Equipment and Features: GN Field, Trans-Am System, Twin Drive System, Trans-Am Raiser, Trans-Am Burst.

Shirou was surprised at the amound of weapons the mystic code has. "Just how many features does this mystic code have?! GN Field? Trans-Am System? Twin Drive System? Trans-Am Raiser, and Trans-Am Burst? What are those systems? Not to mention all those armaments it came with. Did Da Vinci made this out of boredom or what?"

"Shirou-san? Are you all right in there?" Mashu said, snapping Shirou out of his thoughts.

"Hm? Oh, I'm fine in here. Most importantly, I'm worried about master here," Shirou replied as he was looking at Ritsuka constantly looking at him like how an otaku would look like an idol.

Da Vinci laughed a bit. "Don't worry. He's like this when it comes to mecha and anything related to it."

"I can see that...anyways, Da Vinci, are we done yet?"

"Oh. We're not done yet," she said with a grin on her face.

"What do you mean by that?"

"You'll see."

It was at that moment that three certain saber-face servants came into the room, with an excited look on their faces.

"Is it true Da Vinci?! Is it true that you actually managed to give Shirou a mystic code that will make him look like us?!" Mysterious Heroine X exclaimed in excitement.

"I want to see Shirou right now. What kind of mystic code did you give him?" Mysterious Heroine X Alter asked.

"Is Shirou in that mech suit over there?!" Mysterious Heroine XX asked as she saw the human-sized 00 Raiser.

Da Vinci let out a smug grin. "Yes, you three. Shirou's right here!" she said as she pointed to him.

In an instant, like Ritsuka from earlier, Mysterious Heroine X, X Alter and XX immediately came up to Shirou and started looking at him in all the places they could find.

"Da Vinci you little genius! I'll pay you back one of these days, but right now, I need to look at what Shirou is wearing!" Mysterious Heroine X thought.

"This armor...these weapons...and that coloring...I like it!" Mysterious Heroine XX thought.

"Could use some black and red...but I'll take it. And plus, these colors suit Shirou better..." Mysterious Heroine X Alter thought.

As the three mysterious heroines were examining Shirou, Shirou turned to Da Vinci and said, "Uh Da Vinci, what's going on?"

"Well...I need some data on the mystic code...and I had a feeling that you may need help using this mystic code...so I called them in! Anyways, have fun with them!" Da Vinci replied as she suddenly dragged Ritsuka and Mashu to a safe part of the testing room, leaving Shirou alone with the mysterious heroines.

"Wait! Da Vinci-" Shirou said, but she was long gone, making Shirou sigh at the predicament he was in. "Well...guess I'm in your care...Arturia..." Shirou said to the mysterious heroines.

Mysterious Heroine X, X Alter, and XX smiled after hearing Shirou's words. "You sure are," they said in unison.

"So...where do we start?" Shirou asked.

"Well...I guess the basic thing to start would be flying," Mysterious Heroine XX said.

Shirou was surprised with what Mysterious Heroine XX said. "F-Flying?!"

"Yes. And don't worry, it's not as hard as you think Shirou," Mysterious Heroine X Alter said.

"Yeah. It's actually easy once you get used to it," Mysterious Heroine X said.

"Well...if you say so..."

Mysterious Heroine XX smiled. "Excellent. Now, let me show you something first," she said before she started to transform. In an instant, she was in her space mech suit. "Okay, now watch how I do it."

Shirou then watched Mysterious Heroine XX, wanting to know what she was about to do. For a few seconds, she was just standing there, doing nothing.

Then she started to float slowly, and then she was in the fair, right above Shirou.

"See? Now you try."

"Uhm...how though?"

"Well...how about you try to imagine yourself flying? That works when I do it."

"Okay then," Shirou said. "Imagine yourself flying..." he thought as he was focusing himself to fly. After a few seconds of concentration, Shirou managed to get himself floating. As he was floating, he exclaimed in excitement. "I did it!"

Mysterious Heroine XX smiled. "Great. Now try to get to the height where I am."

Shirou nodded and tried to go fly to where Mysterious Heroine XX was. However, he was having a hard time controlling his movements as he floated around before finally managing to reach where Mysterious Heroine XX was.

"Okay. Now try to follow me," Mysterious Heroine XX said as she started to move in a direction. Shirou soon followed her as well. As the two were flying, Mysterious Heroine X and X Alter looked at them in jealously.

"Even though she may be me from the future, that doesn't give her the right to float around that much with Shirou! I want to do that too!"

"When is it my turn...I want to teach Shirou next..."

Meanwhile, Da Vinci was getting some data from the flight test. "Hm, Shirou seems to get the hang of flying. Now let's see if he can do some tricks..." She then went over to the speakers and spoke to Mysterious Heroine XX and Shirou. "All right then, Mysterious Heroine XX, get Shirou to land on the ground."

"As you wish Da Vinci. You heard her Shirou," Mysterious Heroine XX said.

"Got it."

Mysterious Heroine XX then headed towards the ground and proceeded to deaccelerate, landing safetly towards the ground.

"Okay, let's see if I can do the same thing..." Shirou thought as he started to head towards the ground. However, he realized something.

He doesn't know how to decelerate.

Which meant he was at that moment a speeding bullet heading towards the ground.

What's more, he was heading towards Mysterious Heroine XX.

"OH NONONONONONONO! ARTURIA, GET OUT OF THE WAY!" Shirou warned her.

"Shirou-?!" Mysterious Heroine XX's eyes widen as she saw Shirou heading towards her. In an instant, there was an impact as his body slammed right into her, followed up with some dust and rubble from where the two collided.

"SHIROU! MYSTERIOUS HEROINE XX!" Everyone in the room exclaimed and went to where the crash happened as they were worried about the safety of the two servants.

However, as the dust settled, what they saw was completely different from what they imagined.

In the center of the mini crater, Mysterious Heroine XX still had her armor on and was holding onto Shirou with her hands on his head and was holding him at her chest area.

"Ow...Shirou, are you okay?" Mysterious Heroine XX asked.

"Yeah...how about you?" Shirou replied.

"I think I'm fine..."

"Well that's a relief..."

Mysterious Heroine X and her counterpart, Ritsuka, Mashu, and Da Vinci sighed in relief. "Well, at least they're safe," Ritsuka said.

"You can say that. I thought they were going to get hurt over there. Good thing their armors protected each other," Mashu said.

"You can say that. Although we now have an issue to deal with..." Mysterious Heroine X Alter said.

"What is it?" Da Vinci asked.

"Well...for starters...get Shirou off of you, older me!" Mysterious Heroine X said to her older version.

However, Mysterious Heroine XX ignored her, infuriating her younger version and her altered counterpart even further.

Ritsuka, Mashu, and Da Vinci sighed at the sight in front of them. "Oh boy..."

For the next few days, Shirou was practicing in the testing room with Mysterious X, X Alter, and XX about the basics of flying and how his mystic code works. Mysterious Heroine XX would teach him how to fly while X and X Alter would teach him how to use the weapons themselves.

While Shirou didn't mind the additional training he was receiving from Mysterious Heroine X, X Alter, and XX, it created some situations that would confuse him.

For example, every time whenever Shirou comes out of the room with Mysterious Heroine X, X Alter, and XX in tow, the first thing they would do is to cling onto Shirou whenever he goes. In addition to that, every time whenever they would pass by any of the Arturias, Rins, Sakuras, Illyas, Miyu, Luvia, Neros, and Jeannes, Mysterious Heroine X, X Alter, and XX would have a smug look on their faces and cling onto Shirou, making them jealous.

Another thing he hadn't encountered for was how much attention Ritsuka was giving to him. For example, he would always show up in the testing room every time Shirou and Mysterious Heroine X, X Alter, and XX would test out the mystic code.

Speaking of which, so far, they have learned many things.

First was that all of its functions was powered by thought. For example, if Shirou wanted to shoot the missiles, then he can think to do so.

Second was the fact that the GN Swords II, III, and beam saber can emit a beam like how the Mysterious Heroine X, X Alter, and XX's weapons can do.

For some reason, they seemed extremely happy about that, and Shirou has no clue why.

Right now, Shirou, Mysterious Heroine X, X Alter, XX, Ritsuka, and Mashu were in a singularity cleaning up some enemies. As Shirou pulled out his GN Sword III and started slashing some enemies down, Mysterious Heroine X did the same as well.

"How's the sword Shirou?" Mysterious Heroine X asked.

"It seems fine, although I'm still surprised at how Da Vinci managed to create such a thing," Shirou replied as he slashed an enemy down.

"You're telling me. Even me, my altered self, and older self are still surprised at what she just made," Mysterious Heroine X said as she slashed an enemy down with Secret Calibur. "But it does look good on you Shirou..."

"Hey. Unaltered me, we need hurry up with the enemies here so we and Shirou can get to where master is," Mysterious Heroine X Alter interrupted.

"On it," Shirou and Mysterious Heroine X said in unison.

Shirou and Mysterious Herione X and X Alter soon then cleaned up the enemies in their area and headed towards where Mysterious Heroine XX Alter, Ritsuka, and Mashu were. As they arrived, they saw that they had their enemies defeated too.

"So, I take it that everyone here is defeated master?" Shirou asked.

"Yeah," Ritsuka replied as he was gasping for breath. "All now we have to do is finish the dragon that's in the cave..."

"I see...is everyone ready here?"

"Y-Yes!" Mashu said.

"Yes!" Mysterious Heroine X and XX said.

"Yes," Mysterious Heroine X Alter said.

"All right then, let's go," Shirou said.

The group of master, demi-servant, and servants then headed towards a cave where the source of the singularity was.

However, as they arrived, there were received with a giant roar from the cave.

"Incoming!" Shirou yelled out.

Mashu then when in front of them and activated her shield, blocking the roar that came from the cave. As the roar ended, the giant dragon revealed itself from the cave it was hiding in.

"Is everyone all right?!" Mashu exclaimed.

"Yeah. Everyone else?" Ritsuka said.

"I'm okay," Shirou replied.

"Me too," Mysterious Heroine X said.

"Me three," Mysterious Heroine X Alter said.

"Good. Looks like all we have to do is kill that dragon then," Ritsuka said with confidence. However, at that moment, a bunch of dragons appeared out of nowhere, rendering Ritsuka's hopes moot. "Or not..."

Mashu sighed. "Mysterious Heroine XX-san, can you take Shirou with you and take out the dragons?"

Mysterious Heroine XX grinned. "With pleasure! Come on Shirou!" she said as she started to fly into the air.

"W-Wait!" Shirou said as he started flying as well.

"Hey!" Mysterious Heroine X said. "No fair!"

"X, now's not the time to argue. We need to kill the dragon first or else it'll kill us," Mysterious Heroine X Alter said as she drew Cross Calibur.

"Tch...you have a point there..." Mysterious Heroine X muttered as she drew Secret Calibur. "Well, time to kill off the dragon to ease my rage!"

X and X Alter then went for the dragon. Meanwhile in the air, Shirou and Mysterious Heroine XX were fighting off the hordes of dragons coming towards their way.

"Jeez...there's too much of them..." Shirou thought as he struck down a dragon. "Is there any way to finish this faster...wait...that's it!"

Shirou then started to fly away towards where Mysterious Heroine XX was, surprising her when he grabbed her and started to fly away from the dragons.

"Shirou?! What are you doing?! Aren't we supposed to kill the dragons?! Mysterious Heroine XX exclaimed.

"That's the thing. I have an idea..." Shirou said as he whispered into her ears. As he whispered his plan to her, Mysterious Heroine XX's eyes brighten up immediately.

"I see! So that's your plan!" she exclaimed excitedly.

"Yeah. Can you distract them?"

Mysterious Heroine XX grinned. "Yes!"

Mysterious Heroine XX then headed towards where the dragons were and started distracting them. Meanwhile, Shirou was charging his GN sword III. As he was doing that, he started speaking telepathically to Ritsuka.

"Master."

"Shirou?"

"Master, I'm planning a huge attack to finish all of the dragons at once. Once Arturia gives you the signal, tell the others to retreat."

"And what kind of signal would that be?"

"I'll tell you when the time comes. For now, tell the others to distract the giant dragon on the ground."

Ritsuka gulped at what the signal was going to be as he waited until Shirou gave him the signal. "Everyone! Shirou's planning to do something to kill off all the dragons! For now, distract them while you can!"

Mysterious Heroine X, X Alter, and Mashu heard Ritsuka's voice and said, "Yes!" As they were distracting the dragon, every one of them were having thoughts about Shirou's plan.

"What's Shirou planning this time...is it something big or what?" Mysterious Heroine X thought.

"Distracting the dragon at this stage...is Shirou unleashing a huge attack?" Mysterious Heroine X Alter thought.

"What kind of plan does Shirou-san have now?" Mashu thought.

As Mysterious Heroine X, X Alter, XX, and Mashu were distracting the dragons, Shirou was still charging his sword. "Come on...almost there...and...yes! I can use it now!" he thought as he was checking his gauge. "Arturia! Now!" he exclaimed to Mysterious Heroine XX.

"All right!" she replied as she soon flew to where the others were. "Hey dragons! Follow me!" As she flew, so did the dragons too as they followed her. Eventually, Mysterious Heroine XX led them to where the others and the dragon was.

"Master! Now!"

Ritsuka nodded and yelled out, "Everyone get out of here!"

In an instant, everyone moved away to a safe distance, allowing Shirou to do what he was about to do.

"I hope this works..."

*Cue Trans Am Raiser OST*

Shirou then raised his arm that was connected to the GN sword III. "TRANS AM RAISER!"

In an instant, Shirou turned pink and a giant pink beam came from the GN sword III that was several kilometers long. As Ritsuka and the others saw the giant beam coming from Shirou, they were in shock at what he just unleashed.

"Holy shit! That is one big beam! Is this what Shirou was planning for?!" Mysterious Heroine X thought.

"That beam...it looks so pretty..." Mysterious Heroine X Alter thought.

"Wow...Shirou, you certainly have surprised me today..." Mysterious Heroine XX thought.

"Awesome..." Ritsuka thought.

"Is this what Shirou-san was going for...?" Mashu thought.

Shirou then swung his sword at the group of dragons horded together. As he swung his sword, the giant beam came over too, incinerating the dragons immediately, including the main one. Some of the dragons who survived immediately left out of fear of the weapon Shirou used. As the dragons left, the beam disappeared and left Shirou panting.

"So...that was the Trans Am Raiser...just what kind of power does this mystic code have...Da Vinci...just what have you created...or rather copied?" Shirou thought.

"Shirou! Are you okay?" Ritsuka yelled out, snapping Shirou out of his thoughts.

"Huh? Oh, yeah, I just feel a little drained..."

"No kidding. After what you just, I'm not surprised. Anyways, can you come down for a moment?"

"Sure."

Shirou then floated down to where Ritsuka and the others were. However, it was at that moment that the mystic code shut down, releasing Shirou from the armor...and made him pass out and nearly fall to the ground if it wasn't for Mysterious Heroine X, X Alter, and XX catching him at the last moment.

"Shirou/Shirou-san?!" Ritsuka exclaimed.

Mysterious Heroine X checked on Shirou and said, "He's fine master. He's just exhausted."

"Yeah. For now, just let him sleep," Mysterious Heroine X Alter said.

"After all, he did unleash a huge beam attack after all," Mysterious Heroine XX said.

"Well, if you say so," Ritsuka said.

The three mysterious heroines then looked at Shirou with a single thought in their minds and a smile on their faces.

"Shirou, you truly have become one of us..."

Omake

"Hey Da Vinci, can I ask you something?" Ritsuka asked.

"Sure. What is it?" Da Vinci replied.

"Well...can you create another mystic code like the one you gave to Shirou earlier?"

"Well...I can, but why?"

Ritsuka was silent before exclaiming, "I WANT TO BE A GUNDAM TOO!"

Da Vinci looked at Ritsuka in shock. "What?"