Shinji Matou at Your Service

Why save me?

If the Matou family were ordinary people, unconnected to the world of magecraft, Caster wouldn't have found it strange.

But the Matou family wasn't ordinary. Not only were they involved in the Holy Grail War, but they had also already summoned a Servant. That made things quite odd.

The theme of the Holy Grail War was battle to the death. While Masters had various ways to protect themselves, such as severing their contracts or using up their Command Seals, or even seeking refuge with the Church, for Servants who weren't allied with them, the only outcome was death.

Although there's no rule in the Holy Grail War that a Master can only form a contract with one Servant, it's rare for a Master to simultaneously have two Servants. There are two key reasons:

Magical energy supply: Maintaining a Servant's existence consumes a huge amount of magical energy. Ordinary magi often struggle to support even one Servant (with exceptions like Artoria, who has her mana regeneration). Even top-tier magi would find it extremely difficult to sustain two Servants unless they used extreme methods like sacrificing lives or devouring souls.

The final wish: In the end, the Holy Grail can only grant the wish of one Master-Servant pair. If a Master has two Servants, how would they choose in the end?

From Caster's perspective, it would have been far more convenient—and normal—for them to kill her while she was weak.

Shinji understood this logic well, so he turned to Sakura, who was tidying up the dishes and asked her.

"Sakura, why did you decide to save her?"

"When I saw her lying there all alone, I just couldn't help it..."

Sakura instinctively lowered her head and answered in a soft voice.

"Couldn't help it... Are you—"

Caster's eyes flashed with a strange expression, which quickly turned to anger, "—Are you pitying me?"

"I..."

Sakura's shoulders shrank, unsure how to respond.

"Yes, we are pitying you."

Since Sakura didn't answer, someone else did—her Servant, Medusa.

"Rider, don't, don't say that."

"No, I'm going to say it."

Sakura tried to stop her, but Medusa wouldn't listen.

Even though they hadn't been together long, the bond between Medusa and Sakura had already grown very strong. Medusa constantly protected Sakura, proving they were a perfect pair summoned by their compatibility.

"You lost your Master, you're injured, your magical energy is depleted, and you could barely walk, making all those pitiful sounds along the way—how could anyone not pity you?"

"You... you heard everything?"

Caster recalled what she had said, and her long ears twitched. Her ears were the only physical feature that set her apart from modern humans, resembling the long ears of elves from fantasy novels.

"Yes, we heard everything. Every single word."

"Ugh!"

Caster's demeanor immediately deflated.

"Everyone calls me a witch, and in the end, this is what I've become. I just wanted—"

"That's enough, stop talking."

This time, it was Caster who panicked. Pouring out her heart right before death was one thing, but having it repeated to her later was another matter entirely.

"—to return home."

But Medusa wasn't finished.

"Enough! I said stop talking!"

Caster, now embarrassed and angry, lashed out, "You don't know anything…"

"How would we know if you don't tell us?"

"If I told you I killed my own Master with my own hands, and that I was injured while trying to sever our contract, would you still pity me?"

"..."

Caster's outburst left Medusa silent.

Sakura, Fujino, and Kirie were all shocked. According to the monitoring system, Atrum had only summoned his Servant less than a day ago, and now she had already killed him.

Only Shinji, who knew Caster's background, remained calm.

"There's always a reason for killing someone, and you don't look like the type of person who kills for fun."

"Hehehe, you're wrong. People have always called me a madwoman, a witch known for betrayal. I don't need a reason to betray anyone." Caster's voice was sharp, shattering the previously calm and pure impression she had given.

"A witch of betrayal… I see now. You must be the princess of Colchis."

Combining the knowledge granted by the Holy Grail with certain traits Caster displayed, Medusa deduced her identity. Colchis was a kingdom from Greek mythology, famous for the Argonauts who sought the Golden Fleece there. The princess of Colchis was none other than Medea, the wife of Jason, the witch who betrayed both her family and her husband.

"Do you regret saving me now?"

Medea asked coldly.

Before Medusa could answer, the room filled with laughter—Shinji's laughter.

"What's so funny?"

Medea clutched the blanket tightly.

"I'm laughing because of your Master, Atrum Galliasta."

"You knew him?"

"I knew him, but not well. Sakura mentioned that his workshop caught fire in the end—was that your doing?"

"Yes, I'm the one who set it ablaze. I even burned him to death."

"That man used to boast back in England that one of his spells was as powerful as the flames you used to burn your rivals to death in life. And now, he's dead by those very same flames. Isn't that funny?"

But aside from Shinji, no one else in the room laughed. Medea wasn't in the mood, and the others couldn't find it funny. Shinji rubbed his nose, feeling a little awkward.

"If your Master had been someone else, I might have regretted saving you. But Atrum got what he deserved. That guy had a rotten mindset. He was arrogant, but at the same time deeply insecure. Specifically, he couldn't stand anyone being stronger than him. Seeing someone like you, a magus from the Age of Gods, probably made him lose his mind. I bet he did some pretty awful things to you. You say betrayal is in your nature, but you have your wish you want to fulfill, and you know what happens if you lose your Master. I don't think your so-called nature of betrayal is more important than your wish."

"..."

Medea remained silent.

"And what about those women and children? If you were truly a madwoman, why did you let them go? You had no connection to them, right? The answer is obvious: you're not as bad as you claim. We don't regret saving someone who saved so many lives—does that answer satisfy you?"

Shinji smiled at Medea, but she kept her head down, staring at her hands, avoiding his gaze.

"What... what do you plan to do with me?"

"Let you go? That's impossible. The only reason you can stay in the world without disappearing is because of the workshop's effects. If you leave here, you'll vanish soon after due to the lack of a proper anchor. Even if you found another anchor and a source of magical energy in time, I don't want another competitor for the Holy Grail. So, I have a proposal—why not join us and lend us a hand?"

PS: The issue of magical energy consumption is well illustrated in the Unlimited Blade Works anime. Rin could barely manage to support both Saber and Shirou's Reality Marble and Shirou himself had 27 Magic Circuits to supply energy. This shows just how massive the consumption is.