Kaleid Liner Lias' Pawn
by Lunar Wave

Disclaimer: I don't own High School DxD nor do I own Fate/Kaleid Liner Prisma Illya. Enjoy this non-sponsored crossover story.

Prologue: A Strange Young Girl

Illyasviel von Einzbern, daughter of Emiya Kiritsugu and Irisviel von Einzbern, the sealed vessel for the Lesser Holy Grail, Magical Girl, and current wielder of both Kaleidosticks Ruby and Sapphire. Right now, she trudged in a forest, not sure what was going on. She carefully weaved through the forest alone. Scratched, bruised, and still hurting from her last battle. But now wasn't the time to dwell on that. She needed to go. She needed to keep moving. Ruby and Sapphire were both asleep so she can't even fly. Then again, her body was way too tired to even try, even if they were awake. Instead, she continued to trudge on, continuing to reach somewhere safe, somewhere she can rest.

She soon reached a park. Breathing a sigh of relief, only to feel her breath hitch and her heart stop for a second when she saw a boy and a girl there. No, it wasn't that she was scared of being spotted. In fact, she would be very grateful if they could help her. No, the reason why she was scared, why she was so frightened at the moment was simply by virtue of what she heard the girl ask the boy.

"Will you die for me?"

This would seem like some sort of weird marriage question. Asking a person if they would die for them. The romantic people would generally just say yes, or some sort of variant of "no, because I will live for you." But it was instantly clear to her how wrong that thought was when the girl opened her wings. Black, feathery wings, like those fallen angels she has read so much about in various manga and seen in certain anime. Not all of them were good. In her hand was a spear of light. And so, she did what she thought was the only thing she could do. She has neither the prana nor the time to Install a card. It was taking all her effort just to run. But that is what she did. For the boy who was dragged into something he doesn't really know about. She hurled herself at the boy and forced him out of the way. The bolt of light snagged at her back, and she let out a small cry of pain.

Hyoudou Issei was having the greatest day of his life. He was on his first date with his first girlfriend. It was almost the perfect time for him to lose his first kiss. A park abandoned, without anyone around. The sun was just about to set. It was like the perfect place to kiss and maybe even a bit of… Issei chuckled in a very perverted manner. But… the keyword was was. He was having the greatest day of his life. But that all changed with a single question that stabbed at that perfect day. A question from his girlfriend that he was not sure he could answer.

"Will you die for me?"

Everything after that was a blur. Yuuma suddenly grew wings, her hand holding onto a spear that seemed to be glowing, and in an instant the spear was hurled. He didn't even have the time to react. He could barely even process the thought that he was about to die. But he lived, even if it's just for a short while. He lived. Because a little girl, probably in her elementary years, threw herself onto him and they both managed to get out of the way.

"Wh-wha?" He couldn't help but say those words. "Wh-what are you t-trying to d-do, Yuuma-chan?"

"Che, an interference. No matter." Yuuma said off-handedly. She prepared another light spear.

"RUN!" The little girl in his arms told him. He scrambled up, trying to carry the little girl away from there, but it was too late. They were both pierced by the light spear. Him through his stomach, the girl through her heart. When the spear disappeared, both of them simply collapsed on the ground.

"Sorry about this. You were a threat to us so w… Yuuma tried talking to him, but Issei could no longer listen. He chose to ignore her, instead focusing on his thoughts. He was rapidly losing consciousness, and there is no way he would bother listening to her now. He just got a little girl trying to save him get killed. Maybe if he just left her. No… she would've just gotten killed regardless.

Yuuma left soon after, but Issei paid no mind to that. A piece of paper, something he received earlier that day was neatly folded in his pocket. He strained his hand from the little girl's back and in front of his face. Blood. The blood of a little girl that died. Some of his blood must've gotten mixed in it too, but all he could think of was the fact that it was the blood of a little savior. He reached his hand to that paper. It said that it would grant him a wish, right? Well right now he has one. He wants to be reborn. He doesn't want to die here. He had so much to live for!

No… his mind eventually corrected his own selfish desires. What he really wants… is for this little girl to be saved. He wanted to save her.

"I… wish that… I can save her…" These words echoed through the woods. And in an instant, he heard a voice. He couldn't truly understand the words she said. His hearing has long since deteriorated to a mere fraction of what it once was. His eyesight has already started fading as well. The world was a blur: a complete and utter mess of orange, red, purple and black. His sight started growing dimmer too. That must be his eyelids shutting. But before closing his eyes, before truly lost consciousness, he thought he saw a single detail that differed from the sunset sky. Beautiful crimson hair. His eyes closed, but not before he had one last thought. Was this the person that would grant his wishes? Well then…

'I… wish… to save… her...' Haha, how pathetic, he couldn't even say the words when the wish granter arrived.

Rias Gremory stood above the fallen duo. She cursed herself for not having known what happened. She cursed herself for being complacent. Two people just died from what appears to be a powerful bolt of light. That means either angels or the fallen had arrived at her territory and she hadn't even noticed them. And upon inspection of the area, she found a black feather. That means it must've been fallen angels. It was her responsibility now to save them.

The little girl, probably ten to twelve, was lying down on top of Hyoudou Issei, one of the three most infamous perverts in school. It might've been a bit of a scandal if only the two didn't have a hole through their bodies. She grimaced upon seeing the last dredges of consciousness seep away from the boy, even as she told him that he would live for her.

She looked at the two's values in terms of pawn pieces. The girl seemed to be worth three pawn pieces, interestingly enough, but what made her worry the most is the fact that Hyoudou Issei was worth eight. She had no other pieces in her arsenal that could become worth that much. She had already used one of her rooks, so there was no way she could combine two rooks so that the amount would be enough. So she sighed. She may have to part with her last bishop. She quickly decided to leave the girl for later and focus on the one who was worth more. While it seems harsher, she can't help but want such a powerful piece that was potentially worth nearly as much as a queen.

She quickly moved the girl away from the boy's chest and began the process of placing the eight pieces on the chest of the boy. Pouring some of her magic power into it, they began to enter his body. Soon all the eight pieces have fully entered Hyoudou Issei's body. His wound quickly started closing, as his body started being turned. She smiled. Now it was the little girl's turn.

The Holy Grail heard his wish. Although sealed in the body of a dying little girl, although it was similarly exhausted from the battle that the little girl faced beforehand, it still heard such a heartfelt wish. Or maybe it was because the vessel was dying that the seal had become loose enough that it heard such a wish. But nonetheless it heard it. It's nature and, by extension, its vessel's nature is to grant wishes. There has never been any other purpose that it existed for other than to grant those wishes. And, such a powerful wish, coming from an individual whose mind seems to be filled with lust.

The boy wished to save the little girl. He didn't wish for her to just live. He wished to save her. But it wasn't in the boy's capacity to save her. There was no way the boy could save her.

But then a devil arrived. The devil was thinking of how to save both of them. It seems that the devil was willing to save both the boy and its vessel. But that would go against the boy's wish. He didn't wish for the devil to save her. He wished to personally have a hand in saving her. The Grail was willing to reject the devil's attempt at saving the girl, so that the boy could have his shot.

The devil placed eight pieces on the boy. They seem to have the ability to resurrect those who are dying or those who recently died at the cost of turning the person into a devil. And upon learning that particular knowledge, it understood what would be necessary for it to fulfill the conditions of the wish.

"Wh… what?" Rias gasped as she saw three pawn pieces leave the boy's body. She instantly tried to grab them but she was forced back by what she could only describe as a powerful and strange power. She looked bewildered as the pieces moved towards the little girl's back and entered her body, much like the same way their brethren entered Hyoudou Issei's body.

"… Was… that supposed to happen?" The young devil looked shocked. She hadn't done a multiple piece resurrection before and to see something so strange happen was too surprising in many ways. She watched as the girl too started resurrecting. Her wound was also starting to mend. But there was something different. Hyoudou Issei's body was mending, and being turned. But the girl… she wasn't turning. There was no increase of demonic power in the girl. It was healing her, it was saving her, but it seems that upon the completion of their resurrection, the boy had turned fully into a devil, but the girl had remained human.

"Oh… dear…"

The Grail was pleased with this result. The wish that it was assigned to grant was fulfilled. The boy's pieces and by extension the boy himself had saved its vessel. To further make the emphasis that it was the boy who saved its vessel, it removed the ability of the pieces to turn its vessel into a devil. After all, to the boy, the girl turning to a devil would not have been a truly successful saving. At least not right now.

And with this, the boy had saved its vessel. It could feel the seal that its vessel's mother had created for it chain it down once more, as the girl's body realized that it was no longer dying. Truly, this was a successful wish granting. Now, it was time to return to its previous task, the last wish that it granted; the wish that Illyasviel von Einzbern last fulfilled.

Prologue End

Beta read by: Arrixam (Thank you very much)

It's very rare for me to find a story that uses Fate/Kaleid Liner Prisma Illya properly. Especially a crossover. So I decided to take a shot at it. Now let's see if I can clear things up a bit:

The Title.No. I did not misspell Rias. Feel free to come up with why I named this story that way. I'll explain in the next chapter.

Illya being worth three pawn pieces. So, I made Illya worth 3 pawn pieces. No more whining about her being worth more; I have come up with a good way to solve that. But not in this chapter.

Illya not becoming a devil. It would be an interesting contrast to the other scenarios that everyone else has. It was always either, join Rias's Peerage or remain a human and just involve themselves. Of course there are those that go against the flow like making the Devils seem genuinely evil. In this story I chose to add the character into Rias's Peerage, but have to deal with the fact that everyone around her is stronger in general. As well as the obvious: not having the same longevity as everyone else.

Issei's Pawn Pieces. Illya receives Issei's Pawn Pieces for her revival, and I think it's safe to say that I decided to use Grail Ex Machina for that. There are naturally limitations. I'll reveal it in the following chapters. All you need to understand is that the pieces that revived Illya is still very much part of Issei's 8 pawn pieces.

Kaleidostick Sapphire being under Illya's possession. Not right now. No. I won't reveal that story yet. Not yet.