Author's note: Here's the Caster Arturia chapter you guys have been wanting! Don't worry, Proto Merlin will get her time soon...

Update 6/6/21: This chapter is inspired by Ulti-shadow's "The Caster of Avalon."

Anyways, hope all of you enjoyed it!

Today was the day Ritsuka would do his daily summoning at the summoning alter, in which he would drop his hard-earned saint quartz onto the alter and hope that he could summon a good servant.

"Hm...wonder what will I get for today's daily summoning? Last time I got a Caster-class servant named Hakuno Kishinami who happened to be the former master of Saber Nero, Caster Tamamo, Archer Gilgamesh, and another servant named Nameless who happened to be a variant of EMIYA who looks exactly like him, but with a different origin," Ritsuka thought as he placed the saint quartz onto the summoning alter.

It was then that Mashu came into the room. "Senpai?"

"Hm? Oh, hey Mashu," Ritsuka said as he turned around to see her.

"Senpai, are you planning on summoning another servant today?"

"Yeah. After all, today is my daily day for summoning servants, and it's been a while since I summoned someone. Want to see the results?"

"Sure. I don't mind," Mashu replied.

Ritsuka smiled. "Great. Now, let's see what today will bring me..."

Ritsuka and Mashu then looked at the summoning alter together. As they were looking at the alter, the alter lit up, temporarily blinding the two from how bright the light was. The saint quartz then disappeared, then formed into multiple blue orbs. Then the blue orbs started to connect with each other and turned into a ring of blue sparks swirling around. Then the ring split into three and continued to swirl around.

As the light faded, it revealed a gold card showing a robed old man wearing a hood with a long beard holding a staff while carrying a book at the same time. The card then disappeared as a girl appeared.

However, Ritsuka and Mashu received a surprise upon seeing the girl.

Because the girl looked like Arturia Lily, but she was wearing an outfit that looked like a school uniform from a private school along with a hat as well. Not only that, but she wasn't carrying Excalibur or Rhongomyniad. Instead, she was carrying a staff that looked like the one Merlin was carrying, and yet different at the same time. On her back was a short sword of sort.

"Hello there! I'm called Arturia, a caster! To tell you the truth, I don't really get this servant thing. But, if mere magecraft can be of help to you, then please make use of it as much as you wish."

Ritsuka and Mashu were surprised with the new servant's introduction. "Y-Yeah. Hello Arturia, my name is Ritsuka. And over here is Mashu."

"H-Hi Arturia," Mashu said. "Anyways, welcome to Chaldea."

"Chaldea? Is that a name of an organization?"

"Yes. Chaldea is an organization that prevents the extinct of humanity by going into singularities and fixes them."

"I see. Anyways, pleasure to meet you master! I hope that my magecraft can support you as much as you wish."

"Um...Arturia, you don't have to say that you know..."

"Why?"

"Well...magecraft here is actually rare here..." Ritsuka said.

Caster Arturia was surprised upon hearing Ritsuka's words. "Eh? Magecraft isn't "piddling"? Whoa... is that the case in this world?"

"Yeah. So...magecraft here may be different than what you are used to..."

"I see..."

It was then that a certain servant came into the room. And that servant was Saber Arturia. "Hey master, Da Vinci needs to ask...you...for something..." Arturia said as she slowly stopped saying upon seeing her Caster counterpart.

And like her Saber counterpart, Caster Arturia was shocked to see her Saber counterpart in front of her.

"No way..." Saber Arturia muttered as she pointed at her Caster counterpart.

"Um...master, am I going crazy, or am I seeing another version of me over there?" Caster Arturia asked.

Ritsuka nervously laughed at Caster Arturia's question. "Well, you're not going crazy. The person in front of you is well...you, from an alternate timeline that is different from yours."

"I-I see..."

"Um...this may feel a bit awkward to both of you, but...Arturia-san, how about you meet your Caster counterpart for a bit?"

"Y-Yeah." Saber Arturia then went up to her Caster counterpart and greeted her. "Hello Caster me," Saber Arturia said with a smile.

"Ah. H-Hello to you too," Caster Arturia said.

Ritsuka let out a sigh. "Anyways, Arturia."

"Yes master?" Saber and Caster Arturia asked in unison.

Ritsuka sighed again. "Here we go again..."

"Senpai was referring to the Saber Arturia," Mashu said.

"Oh. Sorry," Caster Arturia apologized.

"It's okay. Anyways, what is it master?" Saber Arturia asked Ritsuka.

"You said that Da Vinci needs me for something correct?"

"Yes."

"Well anyways, would you mind giving your caster counterpart a tour of Chaldea?"

"Sure. I don't mind."

"Great. Now if you will excuse me, I need to head for Da Vinci's room," Ritsuka said as he soon left the room.

"W-Wait up senpai!" Mashu said as she followed Ritsuka, leaving Saber and Caster Arturia alone in the room.

"So...should we move on then?" Caster Arturia asked.

Saber Arturia smiled. "I guess so."

Soon, Saber and Caster Arturia soon left the summoning room and Saber Arturia proceeded to give of Chaldea. As she did, Caster Arturia was amazed with how many rooms and facilities Chaldea possess.

"Wow. To think that there were this many rooms in here..." Caster Arturia said in awe.

"Yeah. It's natural to have this reaction to Chaldea here. The first time I was summoned here, I was surprised with the amount of rooms here," Saber Arturia replied.

"I can see that. What's that room over there?" Caster Arturia asked as she pointed at a room.

"That room? Ah, that room is one of the recreational rooms in which servants would go over there to take a break and relax or something," Saber Arturia said as they were walking. As they continued walking, Saber Arturia asked her Caster counterpart a question.

"So...um Caster me, can I ask you something?"

"Sure. What is it?"

"Just how are things different in your world and mine?"

"Well, in your world, I assumed you were chosen by the sword of selection and pulled it from the stone, right?"

"Yes."

"Well, in my world, I didn't pull the sword from the stone. Instead, I was chosen by the staff of selection."

"Is that so?"

"Yup. And ever since then, I've been studying magecraft under Merlin's tutelage."

Arturia was slightly shocked upon hearing Caster Arturia's words. "You trained under Merlin in magecraft?"

"Yeah. Why?"

"Well...nothing. Anyways, let's move on."

Saber Arturia soon continued giving her Caster counterpart the tour. As she did, some thoughts came into her mind. "Really? Merlin taught my Caster counterpart magecraft? Well, at least she's acting like my Lily counterpart. I hope Merlin didn't teach her anything suspicious..."

As they were, it was then that Arturia and her Caster counterpart came across a certain group of servants.

The Knights of the Round, along with Merlin.

"Hm? My king?" Gawain, Lancelot, Tristan, Bedivere, and Gareth said as they noticed both Saber and Caster Arturia together.

"Father?" Mordred said as she did the same as her fellow knights.

"Oh my," Merlin said as he looked at both Saber and Caster Arturia.

"Hm? Oh, hey everyone," Saber Arturia said as she noticed the Knights of the Round coming up towards them.

"My king, who is this person that looks like you?" Gawain asked.

"This person over here is my Caster counterpart," Arturia replied.

"Hi everybody! I'm Caster Arturia! Pleased to meet you all!" Caster Arturia said happily.

The Knights of the Round and Merlin were surprised with the news they just received.

"Haha! Another adorable form I see!" Gawain said.

"I wonder how many versions of the king we have now," Lancelot said.

"Eh? There are other versions of you beside me?" Caster Arturia asked Arturia.

"Yes. Our king has an altered counterpart, a Lily counterpart, a Lancer counterpart, a Lancer Alter counterpart, a Ruler counterpart, an Archer counterpart, a Rider Alter counterpart, a Santa Alter counterpart, an Assassin counterpart, a Berserker counterpart, and a Foreigner counterpart," Tristan said.

Caster Arturia was shocked upon hearing Tristan's words. "You got to be kidding me..."

"Yeah. And that's not counting the look-alikes," Gareth said.

"Eh?! There's other servants here that look like me?!"

"Yeah..." Bedivere said.

"Wow...this is going to take some time to take in..."

"You aren't kidding. Anyways, I'm surprised to see father as a mage, even though I've seen counterparts of my father that don't wield any swords," Mordred said.

"That's right! I'm not good with swords, but I've learned all sorts of magecraft from Merlin!"

Everyone besides Arturia and Merlin were shocked upon hearing those words.

"Oh really? And what did my counterpart in your world teach you?" Merlin asked sweetly.

"Hm...well..."

However, at that moment, Lancelot grabbed Merlin by the collar of his robes and said, "I would appreciate it if you would stop meddling with the king."

"Hey. It's not my fault. Blame that on that other world's version of me..." Merlin replied.

"Uh, what's going on?" Caster Arturia asked.

"Oh, it's nothing. Anyways, if you're in trouble, don't hesitate to speak up. Got it?" Gawain asked.

"Y-Yeah."

"Good. Now if you'll excuse me, me and my fellow knights need to have a talk with Merlin..."

The rest of the knights nodded upon hearing Gawain's words and started dragging Merlin elsewhere. During the dragging, Merlin had a look on his face that said, "Why me?"

"Uh, what just happened?" Caster Arturia asked.

Saber Arturia sighed. "It's nothing. Anyway, shall we continue the tour?"

"Yes!"

Soon, Saber Arturia continued taking her Caster counterpart on the tour in Chaldea. As she did, Caster Arturia then started a conversation with her Saber counterpart.

"Hey, Saber me, can I ask you something?" Caster Arturia asked.

"Sure. What is it?" Saber Arturia replied.

"Well, since you're a saber class, does that mean that your main weapon is a sword?"

"Yes. My weapon is Excalibur."

"Excalibur huh? I heard a few bits about it from Merlin. It's a strong weapon. Do you mind if I can look at it?"

"Sure. Why not." Arturia then summoned Excalibur and showed it to Caster Arturia. As Caster Arturia looked at it, she was in awe over how simple, yet beautiful. "Wow. So, this is Excalibur...it looks prettier than I imagined. Wait a minute, where's the scabbard?"

"Well?" Saber Arturia said.

"It looks amazing. Just like how Merlin told me in the past. Although there's one question I want to ask."

"What is it?"

"Where's Excalibur's sheath, Avalon?"

"Well..."

"You don't have it? Did you lose it?"

"No, I do have it. It's just that...well..."

"Well what?"

"Well...just give me a moment," Saber Arturia said as she soon started to walk away from Caster Arturia, making her confused.

"What's going on? Where is my saber counterpart going?"

After a few minutes of being alone, Caster Arturia had her answer as Saber Arturia was dragging Shirou along with her.

For a moment, there was silence between the three as everyone laid eyes on each other. Especially for Caster Arturia because as she looked at Shirou, she felt something familiar coming out of him. "Who is this person that my Saber counterpart brought over? And why does he feel so familiar? How though, I never met him..."

Then Shirou asked Saber Arturia a question.

"Hey Arturia? Is that another counterpart of you?" Shirou asked.

"Yes Shirou. That is my Caster counterpart from another timeline. Want to greet her?" Arturia replied.

"I see. Hello Caster, my name is Emiya Shirou. Nice to meet you," Shirou greeted with a smile on his face.

Upon hearing Shirou's voice, Caster Arturia quickly stopped thinking and greeted him back. "N-Nice to meet you Emiya Shirou!" she said as she raised her hand for a handshake. Shirou then responded to the handshake and shook Caster Arturia's hand. As they were done with the handshake, Caster Arturia then turned to her Saber counterpart. "Um, saber me, who is Emiya Shirou?"

Saber Arturia let out a smile. "Emiya Shirou is my former master, the current bearer of Avalon, and me and my counterparts' consort."

Caster Arturia was shocked with the statement. "He's the current bearer of Avalon?!"

"Yes."

Wanting to see if what Saber Arturia said was true, Caster Arturia then came up to Shirou and used her staff to see if Avalon was there. As she checked, she immediately knew what the familiar feeling was.

"You were right...so that's what that familiar feeling from earlier was..." Caster Arturia muttered.

"Hm? Did you say something?" Shirou asked.

"Hm?! Ah! It's nothing! Anyways, this is incredible. I've never seen a person bearing a sheath inside of one's body, let alone Avalon..." Caster Arturia said in amazement.

"Yeah. Imagine my surprise when I saw Shirou bearing it for the first time," Saber Arturia said.

"I can imagine that. A person bearing a noble phantasm inside...that's unheard of."

"You can say that again. Anyways, welcome to Chaldea Caster Arturia. I hope we get along," Shirou said with a smile on his face.

Caster Arturia blushed upon seeing Shirou's smile. "L-Likewise! I hope we get along as well Shirou."

Noticing her Caster counterpart's behavior, Saber Arturia decided to step in. "Well then, shall we continue this conversation in the cafeteria? After all, Shirou can make good food over there."

Caster Arturia's eyes beamed up. "How good are we talking about?" she asked.

Saber Arturia smirked. "So good that you won't forget it even in your lifetime."

Upon hearing Saber Arturia's words, Caster Arturia quickly grabbed Shirou's arm. "Come on Shirou! I want to try your cooking now!"

Shirou let out a small sigh. "All right. Let us now, shall we?"

"Yes!" both Saber and Caster Arturia said in unison as Saber Arturia went towards the cafeteria with Caster Arturia following her while dragging Shirou at the same time.

"Well, guess that no matter which Arturia is which, they can't resist good food. Especially mine..."

"By the way, earlier you said that Shirou was you and your counterparts' consort, right?" Caster Arturia asked her Saber counterpart.

"Yeah. Why?" Saber Arturia asked.

"Well...if that's the case...then doesn't that make Shirou my husband already since I'm your Caster counterpart?!"

Shirou sighed as things now just got complicated...

Omake

"Oh Shirou! Your weapon is a perfect fit for my magecraft!" Caster Arturia said.

"You think so?" Shirou replied.

"Yeah! Let's give it some power!" Caster Arturia then twirled her staff around and in an instant, Shirou's katana glowed up for a moment. After it stopped glowing, Shirou checked his katana to see if there were any effects on it.

"Wow, there is a slight boost of power here. Not only that, but the blade feels lighter as well."

"Well?"

Shirou let out a smile. "Thanks, Arturia," he said with a smile as he gave her a head pat.

"No problem!" Caster Arturia said with a smile on her face.

Meanwhile, Arturia and her counterparts suddenly had a weird feeling.

Like if someone was getting ahead of them...