Zouken Matou had not always been called Zouken.
Five centuries ago, his name had been Makiri Zolgen.
Back then, he had been a visionary.
A magus who genuinely believed he could save humanity.
In his eyes, mankind's suffering stemmed from one fundamental flaw.
The flesh.
Human bodies were bound by physical limits, decay, and mortality. To truly liberate humanity, those limitations had to be discarded entirely.
His solution was radical.
If the Third Magic could be deployed on a massive scale, humanity could transcend physical form altogether.
Souls would become materialized.
Death would lose meaning.
Existence would evolve.
Thus began his lifelong pursuit of a method to guide humanity collectively toward the Root.
During his research, Zolgen noticed a recurring phenomenon throughout history.
Whenever civilization faced extinction-level calamities, heroes emerged.
Not metaphorically.
Literally.
Seven at a time.
Digging deeper, he uncovered the hidden structure of the world.
At its foundation existed the Root.
The origin point of all phenomena.
Two great Counter Forces governed reality.
Gaia, the will of the planet itself.
Alaya, the collective unconscious of mankind.
Above that structure stood the Five True Magics.
Each represented a path capable of reaching the Root.
The First Magic: Creation. The power to bring something into existence from nothing.
The Second Magic: Operation of Parallel Worlds. The authority to traverse and interfere with infinite timelines.
The Third Magic: Heaven's Feel. The materialization of the soul. True immortality.
The Fourth Magic: Lost to history. Its nature unknown, though its wielder was rumored to still exist.
The Fifth Magic: Time Manipulation and Destruction. The ability to travel across time and annihilate anything.
Only one wielder of each Magic could exist at any given era.
As long as a True Magician lived, no successor could inherit their authority.
Heroes did not truly resurrect.
Alaya simply constructed perfect replicas.
A vast spiritual archive known as the Throne of Heroes recorded human legends. When summoned, the system recreated an existence based on those records.
To the living, it looked like resurrection.
In truth, it was replication.
After grasping this framework, Zolgen sought out the workshop tied to the Third Magician.
There, he met Justeaze Lizrich von Einzbern.
The two shared the same dream.
They attempted to artificially reproduce the summoning mechanism used by Alaya.
That experiment became the prototype of the Holy Grail War.
But Justeaze was not the true Third Magician.
She was a homunculus created by the Einzbern family, modeled after the missing Magician.
She could invoke the Third Magic.
Barely.
Once every several years.
Nowhere near the effortless execution of the genuine wielder.
Seeking a solution, Zolgen traveled to Japan.
He abandoned his old name and became Zouken Matou.
He approached the Tohsaka family, who possessed access to an exceptional leyline.
He tempted them with the promise of reaching the Root.
Their cooperation allowed the creation of the Greater Grail.
Seven Masters were then lured into the ritual with the promise of wish fulfillment.
The First Holy Grail War was a disaster.
There were no Command Seals.
The summoned Servants ignored their Masters.
Chaos followed.
The Grail was destroyed.
To attempt a Second War, decades of preparation were required.
Zolgen feared he would not survive long enough.
So he turned himself into something else.
A colony of crest worms.
It extended his existence.
But at a terrible price.
His mind slowly eroded.
His original ideals vanished.
What remained was a single obsession.
Immortality.
Rowan Mercer absorbed all of this in silence.
Five hundred years of history.
Five Holy Grail Wars.
And the true structure of this world's magecraft.
"The Five True Magics…" Rowan murmured. "Looks like I'll be paying the Clock Tower a visit after this."
The First Magic aligned closely with what he was already doing while refining his personal world.
The Second Magic would free him from relying on external systems to cross universes.
The Third Magic was now fully understood.
The Fourth remained unknown.
The Fifth would drastically elevate his mastery over time and destructive sorcery.
Rowan released his hold on Sakura and Medusa.
Then he transferred a portion of Zouken's memories directly into Sakura's mind.
The truth.
Everything.
"You know what he planned to do to you," Rowan said gently. "My offer still stands. Choose."
"I accept."
Sakura answered instantly.
She did not care about magecraft.
She did not care about the Grail.
She did not care about the Matou name.
She wanted one thing.
A normal life.
With Shirou Emiya.
That was all.
Rowan nodded.
"I won't tell Shirou what happened to you."
A breath of draconic fire reduced Zouken's frozen body to ash.
Rowan then reached out.
Every crest worm inside Sakura was extracted and incinerated.
The false Grail embedded in her body followed.
Only then did Rowan extend his hand toward Medusa.
The Command Seals transferred.
Clean.
Silent.
Final.
Through Zouken's memories, Rowan understood Sakura's suffering.
Now Zouken was dead.
Shinji was dead.
The Matou estate, its wealth, and its legacy belonged solely to Sakura.
No one left alive knew what had been done to her.
For the first time since childhood, her future was her own.