Disclaimer: I don't own Fate/Grand Order or anything, just the OC. Support the official release.

"Hey, I hope you haven't forgotten our mission." Olga Marie said while continuing to move forward, she did not lag from Ritsuka or me.

"Our… mission?" Ritsuka cutely tilts her head.

Olga Marie's eyebrow twitches. "You have got to be kidding me… have you forgotten the whole point of why we're doing this!?"

Ritsuka nervously chuckles as she scratches her cheek.

"Senpai, it was in the lecture in the Command Room. The one where you dozed off." Mashu states.

I eyed her curiously. 'She fell asleep during something so important? That's not behavior you would expect from a magus.'

"Forget it, Mashu. This idiot probably doesn't even know what you're talking about." Olga Marie sighs. "Fine, I'll explain one more time. Chaldea, the peak of human genius, is the combination of magic and technology, created a perfect simulation of the Earth as a single model observed its past and future, predicting changes in the timeline and reality due to the analysis by the telescope SHEBA observing the future and the system of Laplace and reviewing the past. It suddenly noticed a temporal anomaly forming in the past of 2004 Fuyuki, Japan. The anomaly was named 'Singularity F' and was observed for study. At the same time an anomaly was observed in July of 2016. The simulation no longer detects humanity's presence which predicts its disappearance before the said date. The chance of a connection between these two events is quite high so a group of forty-eight magicians, all potential masters, each of whom had to use their power and the Fate system to make contracts with Servants to further investigate the disappearance of mankind."

Ritsuka nods. "Oh I see! Thanks chief."

Olga Marie massages her temples. "Seriously, how the hell do I keep ending up being surrounded by idiots?" Her irritation continues to rise. "Do you have any idea how bad you made me look in front of everybody!? You're lucky all I did was remove you from the Command Room!"

Mashu gives the woman a concerned look. "Um, Director Marie? I think that might be a little too far…"

"Like hell it is! Thanks to you I didn't have time to properly change!" Olga Marie yells.

I tilt my head. "Why would you need to change? You weren't planning to dive with the others, were you?"

"Of course I was! I had a special Mystic Code made for this mission!" Olga Marie barks out.

[Essentially, she wanted to show off to everyone]

"Jeez, I didn't get to wear it even once and now it's going to go to waste." Olga Marie mutters under her breath before turning back to Ritsuka. "Anyways, you understand your responsibilities and duties as a Master candidate, correct?"

"U-Umu." Ritsuka said.

"Very well. I'm ordering you to be my bodyguard. Work hard." Olga Marie orders.

Ritsuka salutes the director. "Aye-aye, Director Olga Marie!"

Said director deflates and leans on a chunk of debris. "We're screwed."

'Origin, what are their chances are at surviving?' I asked.

[Had we not intervene, their chances of survival would have been less than 45%. Mashu is a defensive type Servant so even though she can tank the damage she wouldn't have been able to deal any herself in turn. Further, she doesn't know the name of her Noble Phantasm which puts them at an even greater disadvantage. Fujimaru doesn't seem to be well versed in Magecraft and Olga Marie is too nervous to be of any help]

"..." I stared as the two girls continue to be in their little world. 'Is there any likelihood of them surviving without our interference?'

[I am giving you my analysis based on current data. Ritsuka and the director are a liability. If they venture any further, they may not survive]

"...ey… hey… HEY, ARE YOU LISTENING!?" A shriek of a voice rings in my ears.

"Hm?" I blink a few times to see Olga Marie standing in front of me with a scowl on her face.

"I've been calling you for a solid minute! What the hell is wrong with you!?" The director screeches out.

"My apologies. I was," I try to come up with a response. "Daydreaming."

"You're hopeless." Olga Marie exasperates. "By the way Fujimaru, do you know what a Servant is?

"I have some basic knowledge of them, yeah." Ritsuka said. "They're basically the highest-ranked familiar in the Moonlit World, right?"

Olga Marie is taken back by this. "Looks like you aren't completely worthless." She praised, or at something equivalent to that. "They are Heroic Spirits. Various historical figures throughout all of human history, creations that were born from the combined idea humanity had about the most powerful heroes and villains, all summoned in spiritual bodies. They are creatures so powerful that summoning them as true living beings is impossible. Therefore by using a certain ritual, magi can summon certain 'aspects' of a Heroic Spirit as well as a fraction of their power, and are categorized into seven classes: Saber, Archer, Lancer, Rider, Assassin, Caster, and Berserker and will be summoned under any class depending on their characteristics." Olga Marie explains. "They are beyond human yet they are tools made to serve humans, hence why they are called Servants. These Servants come into reality bearing the imprint of not only an actual existing person under its name but also what humanity remembers about them. Even if they're gods, they only exist to serve humans."

My eye twitches in annoyance at the last part. "I advice you retract your statement. Servants may be summoned by Magi, but they are not just some tools. They are just as human as you three."

Olga Marie gawks at the statement. "What…?"

Mashu narrows her eyes a little. "Director, you should take back what you said. I'm not sure if I can contain myself."

"Hmph. The Servant you fused with must be an Earth-type Servant." Olga Marie mutters. "Anyways, do you understand?"

"I think so…" Ritsuka said unsure on how to feel about the lecture.

"Servants also have a secret weapon worthy of their legend. The crystallization of a Heroic Spirit's legend and existence-" Suddenly, we're caught off guard by a sudden ringing noise. Olga Marie pulls up her sleeve revealing a silver bracelet flashing blue. She presses a button and a hologram of Romani appears. "You're so annoying! What do you-!"

"Please get away from there right now!" Romani yells out.

[Saint Graph reaction detected. 6 kilometers away from your current location]

Mashu lifts her shield. "It's an enemy Servant!"

Later

The scene switches to show the four of us running through the burning wreckage of the city.

"I don't understand. What's a Servant doing here!?" Ritsuka asks.

"It's a Holy Grail War." Mashu reveals.

Ritsuka looks at Mashu in shock.

"It's been confirmed that in 2004, a special ritual called a 'Holy Grail War' took place in this city. A Holy Grail is a magical vessel that contains the foundations of all forms of magic. Mages in the city of Fuyuki completed a Holy Grail, and summoned seven Heroic Spirits to activate it. The seven Masters battled it out, and in the end, the survivor obtained the Holy Grail." Mashu states. "However, the conclusion was never recorded. Did the ritual succeed? Did it fail? Who was the victor?"

"What is she talking about...?" I asked.

[A contradiction. The World cannot determine the result because "outcome" never existed. As a result, this timeline has been trapped in a self sustaining loop of destruction until an outcome is recorded. Without a Quantum Time-Lock, history spiraled out of control and this World morphed into this hellish wasteland that if left alone could infect the rest of this Route. We need to destroy it at the source before that can happen]

We run out of the city and end up in what looks to be Riverside Park. "Whatever happened, the Servants' actions ended without anyone knowing about them."

"But why?" Ritsuka asks.

"Fou, Fou!"

We stop as chains suddenly appear in front of us, wrapped around two poles making a fence of some kind.

[This magical energy… its sinister]

Ritsuka walks forward. "Are these… chains?" She tries to grab them.

"Don't touch them!" I yelled causing everyone to flinch.

Suddenly, a chain untangles and attempts to wrap Ritsuka's arm, but the girl manages to avoid it though falls to the ground.

"Master!" Mashu rushes to Kitsuka's aid as the chain goes back to its original position.

[Those chains are like a Venus Flytrap, tricking their prey into believing their harmless until it's too late]

"Too bad." A feminine voice catches our attention. "The fresh prey got away." We turn around and see a figure materializing above us. She is a woman wearing a ragged black cloak with some bits spreading outwards giving it the appearance of broken wings. Her face is hidden under her hood but you can still see her beautiful face and long violet hair flowing down like a river though the color seems to have faded and her golden eyes. On her right hand is a scythe that somewhat resembles a fish hook.

"An unknown Servant and an unknown Master." She seductively licks her lips. "Ah~ How youthful and fresh…"

The moment I saw her face, my head starts pounding. Images of a purple-haired woman appeared reading books, but her face is garbled up.

The headache quickly subsides and I saw her status screen.

[Analysis Complete]

Servant Lancer

True Name: Medusa (Alter)

Strength: ?

Endurance: ?

Agility: ?

Mana: ?

Luck: ?

NP: ?

Description: A Servant of this Holy Grail War. After her defeat, she was Blackened and resurrected by the Grail. She behaves psychopathically, killing people with her eyes, including her Master, and fighting like a vicious beast. She taunts her enemies and has some sense of sarcasm, being very cruel.

"... Medusa." My voice catches everyone's attention.

"Medusa?" Ritsuka said, having heard what I just whispered.

"Are you serious!? Of all the Servants we could have encounter it has to be the bloody Gorgon herself!" Olga Marie exclaimed.

Mashu steps forward and stands behind her Master. "A Servant? But I don't see her Master…"

Olga Marie raises a finger gun at the servant. "This world has already gone mad. A Servant without a Master shouldn't really surprise us."

Medusa Alter walks towards one of the statues and caresses its face with her long talons. "Those are…"

"Former humans." Olga Marie finishes. "Looks like that Servant turned them all to stone."

Behind her are dozens of statues, all of them entangled in her chains with faces frozen in agony.

"Why would you do this!?" Ritsuka demands.

"You have a problem with it?" M. Alter asked. "When you wander into my hunting ground, I'm free to treat however I please, am I not?" She leans into the human statue beside her and, with a sadistic smile, rips its head right off its neck. Blood bursts out of the stump like a fountain covering her right side in blood as the statue's head falls beside us. "Do not worry. I've lost one statue, but now I'm going to have four new ones." She licks the right side of her face as the rest of the blood is absorbed into her body.

[She is using her victims' vitality as a mana source to replenish her own magical reserves. That's how she's been able to exist here without the help of a Master]

Mashu stands firm, her shield positioned in front of her. "Our only option is to fight."

"Fight?" Ritsuka asked.

Olga Marie glances at Mashu. "Can you handle her?"

"Ye-" Mashu doesn't finish as she sees me running straight for her.

"Eliminate." I said.

"Oh, how bold. How fresh~" Medusa Alter said. "To think someone as handsome as you would be-" She didn't finish as a fist made contact with her face, the force sending her flying through the statues and into a nearby building.

"Wow…" Ritsuka gawked.

"He just punched a Servant and sent her flying!?" Olga Marie ogles at what just happened. "A magus, let alone a human, can't so much as touch a Servant! How is this even possible!?"

"Fou, Fou!" Fou barks out.

I get into a stance as the form of Medusa Alter makes her way through the dust cloud and out of the building. "Impressive, it's been a long time since a man has forced himself on me like this." She licks the blood on her mouth. "I think you might just be my new favorite person~" She elegantly motions her scythe and enters a battle stance. "I hope you can give me some entertainment before I kill you."

I clench my fists and charge forward at inhuman speeds, surprising the trio. I pull my arm back for an attack but Alter vanishes before it can connect. She reappears behind me and swings her scythe down but I manage to lift my leg and kick the blade away causing her to miss. She quickly recovers and twirls her scythe around and uses the sharp end on the bottom to try and run me through, however, her attack is blocked by a hexagonal-like barrier.

[Noble Phantasm deployed. Type: Barrier]

"Don't think you have the upper hand just because you have a weapon." I told her.

"I see, I see! This is excellent!" She sends a barrage of attacks at me though they are deflected. "But be careful. My lance is the Immortal-killing Lance. Any wounds this lance delivers cannot be healed by any means, even if by some miracle you manage to completely heal your body."

"I know." I began. "The Immortal Slaying Scythe, Harpe. It removes the undying attribute of anything that it strikes. It's similiar to Diarmuid Ua Duibhne's Gáe Buidhe where it nullifies any magecraft it comes into contact with. Only two people in the world can fully use that scythe: Medusa and Perseus."

"Ara, ara~ You are quite insightful. You must know quite a lot about my legend." M. Alter praises. "Why is that?"

"I have an entire database of every legend within the Human Order. Your legend is one of the many I can call upon." I replied truthfully.

"Intriguing, however, it does not matter. Even with that knowledge, if you make the slightest error," The sharp tip of Harpe surges with power as it rips through my A.T. Field. "You'll find yourself in a world of pain!"

The Blackened Lancer sends her scythe straight for my head, but I twist my body so that it misses, only managing to cut a bit of my hair. I push forward and deliver an uppercut that sends her body upwards, however, she manages to straighten herself and lands gracefully on top of her chains. "Being too fresh can grate on the nerves." She takes her arms behind her head and drops her hair but as she does her hair spreads out and briefly transforms into snakes before turning into chains. The chains spread out everywhere trapping us in a box where we can't escape. "I will entangle you all with my hair."

Mashu and I stand in front of Ritsuka and Fujimaru, ready for anything. "Mashu, I am in need of assistance."

Mashu raises her shield in preparation for combat. "Understood. Senpai, director please run!"

"Mashu…" Ritsuka said.

"You got guts." An ethereal voice catches us all by surprise. "A little girl is a little girl, but you seem pretty strong. The boy next to you is no pushover either. That's why I can't leave you both like this."

"Who are you?" Medusa Alter asked.

"Who? Look at me and you will know…" A person materializes outside the cage of chains. "Old friend."

He is wearing a light blue robe along with a white skirt strapped to him by a white belt. His head is covered under his hood. Underneath the robe, he is wearing a black skin-tight long-sleeved shirt and an arm guard on his left arm. Next to him is a wooden staff of intricate design with a golden ring piece attached to the end of the staff.

"You…" Medusa growls as she recognizes the Servant. "Caster!"

Caster pulls down his hood, revealing a man with long blue hair and red eyes wearing silver earrings.

[Analysis Complete]

Servant Caster

True Name: Cú Chulainn

Strength: E

Endurance: D

Agility: C

Mana: B

Luck: D

NP: B

Description: A Servant of this Holy Grail Way. Originally intended to be summoned as a Lancer, the Norse God Odin, having foreseen future events, used Cú Chulainn as a proxy in order to help him save the Human Order. As a result, he was transformed into a Caster and was given some of Odin's Authority. Despite this, Cú Chulainn is the persona in control of the body.

"... ugh..." Another headache rises and another image appears. This one of a man with a red spear. "... Cú Chulainn... you are Cú Chulainn." I comment.

"Hoh? You recognize me? Even in this form?" Cú asked. "Man, that is impressive."

"Cú Chulainn? As in Ireland's Child of Light!?" Olga Marie yells. "But he uses a spear! How is he qualified to be a Caster!?"

Alter narrows her eyes at the newcomer. "Why do you side with these wanderers?"

The Hound of Culann gives her a look. "Because it's better than being on your side, of course!" He waves his hand and runes appear, which then turn into magic orbs that fly straight for Medusa. The Blackened Servant of the Spear has no time to react and the orbs explode right in front of her. The chains become undone as Medusa falls to the ground.

Cú Chulainn walks down the hill and stands in front of us. "I'm a Caster Servant. For a certain reason I consider you an enemy." He began. "The enemy of my enemy is not necessarily my ally, but for now, you can trust me." He glances at Mashu. "Get in position, young lady. Skills aside, your courage is second to none. Yours too, young man."

[It's really odd hearing Cú Chulainn saying things like that; likely due to him being summoned as a Caster]

"Thank you!" Mashu takes the praise and straightens herself.

I nod.

"Kid!" Ritsuka jolts a little. "Are you her Master? Then I'll leave it to you for the commands."

"I-" Ritsuka takes a deep breath and steels herself. "I'll do my best!"

"It'd be a temporary contract, but out of courtesy for your friends' bravery I'll become your Servant." Cú Chulainn said.

Lancer looks at the exchange and smiles. "Fine by me. It just means I get to kill you earlier than planned." She proceeds to stand up. "I'll take you on while you're still flesh and blood." The chains around us shift and merge before launching themselves at Caster who simply jumps out of the way as their collision smashes the ground. The chains quickly follow in pursuit at breakneck speeds but Caster manages to dodge them all. Alter jumps up and attacks Cú with her scythe but he raises his staff to block the attack. The force behind the attack sends Caster to the ground but is given no breathing room as Lancer soon continues her assault through her garden of statues though the former Hound is nimble enough to dodge her attacks.

The four of us (well five if you count the furball) watch in anticipation as the two Servants fight each other.

Caster continues to dodge but is soon driven into a corner, so with no other option leaps out of there with Lancer in toe. "It seems all you do is run away! You don't even have time to cast a spell right?" Medusa attacks again but Cú manages to dodge at the last second, cornering him in front of a ruined building. "This is what you get for opening your big mouth. This is what happens when you express your intentions." Alter raises Harpe ready to end this.

Instead of fear though, Cú Chulainn smirks.

Medusa looks at him perplexed.

"Young lady!" Mashu suddenly appears in front of Cú Chulainn blocking the attack, causing her to be sent backwards.

"Tch." M. Alter suddenly feels a force sending her down to the ground. When she looks, she sees me with a raised leg as the cause.

"Nice work, boy." Cú Chulainn praised. "I don't need to chant a spell to use runes. Go back to school, you dimwit!" He raises his hand and a rune suddenly appears under Medusa engulfing her in flames.

"AAAAAAAHHHHHHH!" The flames stop and the Servant is weakened but is too stubborn to fall. She takes a defensive stance but it's useless as more runes appear in front of Caster and fly straight at her creating an even bigger explosion than before. The smoke dissipates and Medusa's body begins to break down and disappear, a look of despair plastered on her face.

Ritsuka and Olga Marie are awestruck by what they saw before turning towards Cú Chulainn.

"And that's one down." Cú Chulainn said.

Mashu walks up to him and bows. "Thank you. You saved us when we were in danger."

Cú Chulainn leans in and grabs Mashu by her shoulder. "Well good job. We were saved because of your support. Don't worry about it." He winks and begins to rub on her shoulder, making Mashu unsure on how to react.

Suddenly, the two are separated by Ritsuka who's a blushing mess. "Oi, oi, oi!" Fou jumps from her shoulder to Mashu's and hisses at the Cú Chulainn.

The former hound laughs. "You both have nice bodies!" The two girls don't really know how to react to that comment.

Olga Marie deadpans at the scene. "That's one sexual harassing old pervert." She glances at the only other guy in their group, standing over where Lancer originally was.

[Unfortunately, the data I retrieved is badly corrupted much like the rest of this timeline. It has been tampered with before the World could place it in a Time-Lock]

"I see... thanks anyway..."

"Hey… are you alright?" A voice snaps me out of my thoughts. I turn to look and see Olga Marie standing in front of me. "You like you're on the verge of crying."

"I am fine." I told her.

The director did not buy that one bit. "Cut the crap already. It's obvious something is bugging you, so tell me what it is." She said, "and also how are you able to fight toe-to-toe with Servant? As far as I know, not many humans are able to fight against Servants and win."

"That is none of your concern. We must find the source of this anomaly and destroy it before it can do any irreparable damage to the timeline. Any unrelated enquiry is irrelevant." I coldly stated.

"Wha...? Fine! Be like that, I don't care anymore!" Olga Marie stumps off and joins the rest.

[That was pretty harsh of you, even to someone like that girl]

"I suppose... but I am sure she will be alright."

[Whose to say she will? We barely know much about her and from what we've heard she has to carry a heavy burden by herself but is too prideful to really ask for help. You may want to apologies to her after this is over]

I let out a tired sight and spare one more glance at the spot before walking back towards the others.

Noble Phantasm used:

Absolute Terror Field: Soul Sanctuary (B) Barrier Noble Phantasm

The light of the soul, a physical manifestation of mankind's inability to change... to understand each other. An impregnable barrier that manifests in the form of a two dimensional octagon. It closes the user off from the rest of the world, effectively creating a separate space; it can be considered a Bounded Field. It can block attacks that are B-rank or below as the attack is "rejected" and will bounce back to the opponent.

A Quantum Time-Lock is a "universal" event iterated at regular intervals within a domain for the purpose of anchoring "the average expression of phenomena and occurrences" as immutable absolutes within a confirmed History.

Though the "Universe" permits the birth of unlimited possibilities, countless Adjacent Worlds, and divergent developments of history, as the unrestricted propagation of this process would quickly exhaust the Universe's lifespan, those extraneous Worlds (Routes) removed of the category of "timelines characterized by strength and stability" are periodically culled by the existence known as the World so as to prevent the needless expenditure of energy. The facilitation of this process is referred to as the Conservation of Phenomena, effected by way of heuristic audits of cumulative timeline survivability —judging the persistence of a timeline's Parallel Worlds Branching Potential across the subsequent century.

If left alone, the Great Tree Known as Time will branch without restriction, and the behavior of culling serves to remove those divergences that are unnecessary, leaving only the "trunk" to advance. This is the simplest image by which to comprehend the phenomena. Worlds that lie within the "trunk" are said to be "comparable" (Worlds comparable to others) of "Foundation" (Foundation of a World); the human civilizations extant within them largely resemble one another in expression and format.

Blackening, or Darkening, is a process by which a being is tainted by an outside force, causing their personality to be reversed toward the orientation of evil. For Servants, this is one of several processes that can lead to a Servant becoming an Alter. There are several different processes that can blacken a being.

Heroic Spirits that come into contact with the mud from the Fuyuki Holy Grail, tainted by All the World's Evils, gain bodies of cursed flesh, and they are tainted by it as well. The contaminated servant's personality reverses toward the orientation of evil. The blackened Servant is incarnated by the power of the Grail so the more concrete ties to the physical plane turns them into powerful beings. Their physical interference power increases, but at the same time, they lose the ability to return to spirit form. They no longer bother to restrain their magic energy consumption, so their fighting ability jumps significantly. They do not have precise control, but their destructive power is increased. Their momentum can be likened to a runaway car that never runs out of fuel, so fine handling is impossible because it is out of control.

They are fearful beings inflicting havoc and death upon the world. These are blackened Servants like Saber, completely corrupted and changed into Saber Alter, while someone with an extremely strong ego like Gilgamesh was able to resist the majority of the effects. During the Heaven's Feel scenario, Archer states that distorted Heroic Spirits like himself and the True Assassin have some resistance against the tainted ichor and corrupting influence of the Holy Grail.

Immortal Slaying Scythe, Harpe is a divine sword from Greek Mythology used by Perseus to kill the Gorgon Medusa and one of the many weapons inside Gilgamesh's Gate of Babylon. It is described as a monster-killing holy sword with a special shape similar to a scythe, having the cutting edge on the inside of the blade, though it isn't actually an outstanding sword by itself. Its true strength is its trait of Refraction of Longevity, which is a divine ability that nullifies the "undying attribute" of immortals and inflicts wounds that cannot be restored by any methods other than healing in accordance to the natural laws. It is one of the five Noble Phantasms given to Perseus, the greatest amount of legendary artifacts given to a single person in Greek history, for his quest to slay Medusa. It was given by Hermes, and as it was returned to him once the task was completed, it can be called an "Anti-Medusa" weapon.

Diarmuid Ua Duibhne, also known as Diarmuid of the Love Spot, is a chivalrous man and the first warrior of the knights of Fianna. Because of a magical love spot granted to him by a young girl. Any woman who gazes upon the spot instantly falls in love with him, which eventually leads to an encounter with Grainne, the bride of Fionn mac Cumhaill. Gráinne, having fallen in love with Diarmuid at her wedding party, placed a geis upon him to run away with her.

It has been said that, even while at large, Diarmuid stuck to his fidelity to Fionn and did not lay a finger on Grainne. They were pursued relentlessly by Fionn, but after much blood was shed, he decided to recognize their marriage, granted Diarmuid a proper title and land, and welcomed them back as subjects.

Sometime later while hunting with Fionn, Diarmuid was fatally injured by a Demon Boar, the reincarnation of his half-brother. Fionn, who had the ability to transform spring water into a powerful healing agent was with him, so he had no fear of death. Fionn only needed to walk a few steps to the nearby spring, but with jealousy and hatred towards Diarmuid on his mind, he spilled the water twice. By the third time he went to scoop water, Diarmuid had already succumbed to his wounds.

Author Notes

EDIT: 7/5/2023

Here's chapter two since apparently you guys want me to continue this story. I haven't been feeling that great lately and I just recently failed my road test so I'm all kinds of sad right now. Anyways, Frank is pretty much depressed having to fight and kill Medusa but he'll have to get himself out of there soon because things will get more hectic from here.

What do you think? Send comments/reviews.

Peace~