A/N : This is in an A/U where the events of Heaven's Feel takes place, but Shirou still loves Saber.
Fate/stay night - Light's Spark
Shirou's POV
Tomorrow is the day that Rin and I decided we would go stop Sakura from consuming this world. I spent most of the night projecting Tohsaka's Gem Sword, and hopefully with it a chance of winning this seemingly impossible fight. It will be my job to hold Saber at bay while Tohsaka takes on her sister. My heart is heavy, because everytime I try to envision the upcoming battle, all I can picture is Saber sitting in my dojo, rays of sunlight streaming past her face. Her brilliant green eyes, just like emeralds, staring at my own, as she calmly said "Welcome home, Shirou."
Can I really fight her? Deep down I know I love her, the slight girl who solemnly vowed to always be my sword. I tell myself that she's no longer the Saber I once knew, that the Saber I love is no longer in this world. Half heartedly comforting myself with that thought, I slowly drift off to sleep.
Next Day
Tohsaka and I have a quiet breakfast before preparing to leave for location of the Great Holy Grail. On the way, we solemnly check our strategy over and prepare for the consequences of this battle, if I cannot subdue Saber or she cannot beat Sakura. With pits in our stomachs, we reach the cavern. As expected, Saber is standing there, a silent guardian in the gloom of the cave. "Go. I can stop Saber." I say as confidently as I can manage through all the emotions fighting to break free. Saber simply looks at me. "Are you sure you want to do this, Shirou? You could never best me, even once. You are simply throwing away your life." My heart skips a beat at hearing my name. I do my best to remain unperturbed, and remind myself that this is not Saber.
Projecting Kanshou and Bakuya, I dash to Saber. As expected, she easily repels my attack. All I need to do is stall for time, not win. I just need to buy enough time for Rin to kill Sakura. Instinct drives me forward, telling me that I need to stay on the offense to even have a chance. Saber blocks all my strokes without effort, and starts to press me back. "This is it," I tell myself. I have to use it. Triple-Linked Crane Wings.
"Spirit and technique, flawless and firm
Our strength rips the mountains
Our swords split the water
Our names reach the imperial villa
The two of us cannot hold the heavens together."
As I launch the third attack that would defeat Saber, something stops me. I flash back the girl who appeared in the middle of the night, saving me from lancer. "Are you my master?" she had asked. In that moment, I knew I couldn't follow through. I drop the third pair of Kanshou and Bakuya at my feet. Showing no mercy, Saber instantly stabs me through my heart. In a curious and detached tone, she asks "Why do you not follow through?" I know why. There's only ever been one answer. I choke out "Because I'm your master - and I will always love you."
Saber's POV
I feel a blinding rush of clarity. The controlling voice in my head no longer binds me. My horror mounts as I see Shirou falling to his knees, blood streaming from his chest. As I catch him, I whisper through the tears in my eyes "I'm sorry I couldn't be your sword. I will always love you, and I will always be waiting. Find me in the next world, Shirou." With that, I set my holy sword on the ground, and fall upon it.
END