After preparing necessary items for summoning ritual, Rin stood silently at the side as she was deep in thought.

As per their original plan, the mansion's basement was already modified to accommodate the ritual. All required materials were organized there, ready to be used in case of a sudden need for it. 

As she waited for the optimal time to summon her Servant, Rin glanced at the familiar red jewel necklace on her hand. 

"This thing seems to have a connection to a famous hero, but why did father not say anything about it... Still, I wonder who's my Servant will be. Hehe~

Ugh, I can't get the strongest Servant, Saber, but I still can get next stronger Servant, right, right? 

Either Lancer or Archer works for me! At least let my Servant be stronger than her Servant." 

Rin smiled gleefully as she wonderfully imagined her Servant triumphed over Luvia's Servant. When she finally got over the initial excitement, she looked at the clock and realized there's still some time before 02.00 AM. 

Rin looked upward, saying softly, "hmm, they're talking bit longer than I thought. I wonder..." 

When Rafi came out of Botany Department Library with a quiet woman, Rin realized that woman seemed to hold a clue for Rukino's condition and her cure.

Although she was curious, she knew it's not appropriate for her join in their discussion; it was their private matter after all. Besides, she had her own summoning ritual to do. 

"Still, it's not wrong of me to worry slightly, is it? They're my cooperation partner after all. Yeah, it's because we're in cooperative relation. There's no other reason." She nodded to herself as though she had found the reason she'd been looking for. Though, it's apparent from her face that she was genuinely worried for them than she thought she was.... 

There was some time before the appointed time, so after she calmed down, she went into meditation to gather more mana from surrounding area. 

The mansion luvia bought might not be in direct contact to large spiritual leyline - which was controlled by the Clock Tower. But there's a tiny branch of leyline from the main spiritual leyline which passed under the mansion. It was the reason they decided to prepare summoning ritual in the basement, as that place was nearby to a spiritual energy source. 

It was calm and silent night as usual for her. However, as she thought of that, Rin felt a sudden surge of strong spiritual energy from above. That burst of spiritual energy was so heavy that it's impossible to come from human magus. Just as quick as the first outburst, another strong spiritual energy filled with wariness spread out as though competing with the previous outburst. Although it was clear to her that the second outburst of spiritual energy was way weaker than the first one.

'It's the Servants! But there are only their own Servant in the room... so why did it feel like they're going to fight?' 

A Servant should be faced with another Servant. It was the main rule of Holy Grail War. Because it was widespread knowledge that human couldn't go against Servant toe to toe. There was some exceptions of course, but those cases were pitifully rare. 

There were two voices inside Rin's mind. One said she should quickly check the situation there, who knew perhaps she could be of help. While the other one rationally spoke that, considering it's a conflict between Servants, even if Rin went there she wouldn't be much use with her current ability. Although, it would be a different story if she had a Servant on her side. 

As her sound judgement seemingly won her mental battle, the summoning circle in front of her glowed brightly, surprised her. 

Quickly, a man in black and red battlesuit appeared in front of her. He seemed to evaluate Rin as if deciding something. After a brief silence, he said matter-of-factly, 

"It seems you're my current Master. Let's make this clear first, I will decide how the War will be. Don't restrict my actions, you can just stay safely in this place; I'll be giving you the win. How's it?"

There was only one thing in her mind as she felt a connection formed between her Command Spell and the Servant in front of her, 'D*rn it! What a bad luck!' 

..... 

"Calm down, Gawain." Rafi spoke calmly.

After Caster suddenly said those words, the situation in the room became heavy and tense. Gawain quickly drew his sword and stepped forward to shield Rafi. 

Although Hinako Akuta seemed unmoved, but she quietly raised her guard in case there's a fight broke out soon. After feeling Caster's spiritual energy spike, she realized it would be tough to keep her abilities hidden. Although she felt that she should be a bystander in their conflict, but she had a hunch she's deeply related to it somehow. 'Ahh, what a worse day it is.' 

"You can rest assured. I have no intention to fight, Gawain, Miaoyi. I just want to 'talk' with him properly." Chaotic energy around Caster slowly subsided after she removed her concealment. 

For Caster, after her hidden seal on Rafi was broken, she knew it's pointless to stay quiet all the time. She didn't know what's the cause for her seal to break as the events played differently from what she predicted. Even so that's a fact her seal was broken, and it meant that event in the future would largely occur again in this timeline. Since 'it' couldn't be prevented, then she would just let nature took its course; not to mention she had prepared another insurance which should soon be completed. 

"...first of all, why did you say that, Rukino? What happened- no, what would happen in the future?" Rafi walked away from Gawain's protection as he looked deeply at Caster. 

"But, Master?" Gawain said in caution. 

"It's fine." Due to Rafi's insistence, Gawain relented as he stepped away. But he still kept his guard up in case something happened. 

"Are you sure? She doesn't look completely fine right now though." Hinako Akuta remarked, glancing at him. 

"*sigh*....."

Ignoring Hinako's remark, Rafi went to Rukino's side. He knew that whatever caused that order for her was not that simple. Besides, considering she kept quiet all the time previously and decided to reveal it now meant that something must had happened. It might be a blind trust, but he knew Caster wouldn't really hurt him; he believed she's still the Rukino that he knew. As he came closer to Caster, he went to wipe her tears gently. 

Caster didn't resist, she held his hand close to her face as she felt reluctant to let it go. Although she had already been together with him in these few days, she had to stay in disguise - trying to evade the Dungeon world's detection. Now that her preparation was almost complete, in addition with the seal she left on him broken, she decided to let go of her previous inhibition. Either way, it's not like she could exist for long time even if she stayed like that...

"...as I thought, it still feels the same..." Caster spoke softly. 

Seeing Caster seemed to reminisce her memories, Rafi stayed silent as he then embraced her. They stayed in silence as though they didn't want to ruin that atmosphere. 

Gawain began to relax slightly as the worst situation he imagined didn't happen. 

While Hinako Akuta looked sideways as she didn't want to get more diabetes from looking at that scene. 'These damn couple! Can't they find other place to do it?! ...still, how good would it be if Lord Xiang Yu was here...?' 

After a period of silence, Rafi let go of Caster after she calmed down. 

"Please tell me, what would happen later, Rukino? Can I do something to it?" 

"Hmm, it's a bit of very~ very~ long story, do you really wanna know?" 

"We have the time we need." 

"Are you sure? I was just going to say there's a quicker way to tell it. If you don't want it, that's fine for me too~ " 

"....." 

"So, how is it?"

"Eh, you're really quite different now." Rafi said wryly seeing her playful smirk.

"You bet." Caster gave him a look. 

"Ok. Let's do it your way then." 

"You sure?" 

"...I have a not-so-good feeling about this, but yes I'm sure." He felt a tingle on his back when he saw her strange expression.

"Hmm, it may hurts a bit. But you surely won't mind such little pain, right?" Caster smiled happily. 

In response to her words, Rafi became slightly pale as he saw how happy Rukino was at the prospect of his pain. 'Holy shiet! Just what did my future self do that caused her to hold this much resentment?! Looking at it, it seems like I have wronged her many times?! Damn you my future self, I haven't even done anything...!' 

"Wait, wait, how about we take it slow-" 

"There's no regretting it now." With a smile, Caster quickly did something unthinkable to those present in the room. 

Stab! 

It was a quick and clean thrust straight to the center of his chest, piercing through his back. What did the job was the black sword which Caster held all along. 

"Master!!" Gawain's mana spiked again, even stronger now after seeing that unbelievable sudden turn of event.

Another person in the room was also shocked after seeing such stark contrast of event. Just imagine, they were embracing closely just seconds ago, as if they wouldn't let go of each other. But then it immediately turned into such a fucking tragedy... even for Hinako Akuta who had experienced life through thousands of years, that scene was still a stunner. She couldn't fathom why the heck the previously loving reunion event turned into a bloody one...

"...w-why...?" 

"I said it'll hurt a little, Rafi. Besides, it's also a punishment for you. Hmph. How dare you leave me alone back then?" Rukino puffed her cheeks slightly as she pouted and complained. A protective barrier rose around her and Rafi, preventing Gawain from coming close to them. 

It was then the door was opened as Rin entered the room. Behind her was another person; a white-haired man clad in black and red battlesuit. Similar to those in the room previously, they're equally stunned after seeing such scene right after they stepped in. 

"...can anyone explain to me what's happening here?" Rin asked, dumbfounded at the sight she saw.

..... 

Unknown to those at upper floor of the mansion, after Rin and her Servant walked away, the summoning ritual glowed a little before a silhouette emerged silently. 

"Hmm, why did I appear here? I thought I was still having a blast of drinking in the last pub, or was I...? Ah, a mission... But, hey, I've never signed myself as one of those Counter Guardians!" 

[.....]

[Refusal denied.] 

"...shiet! The system's broken. It actually replied!"