Rin Tohsaka finally understood what Illya meant.
"Could it be—"
"That's right. What the Einzbern family originally wanted from cooperating with the Tohsaka family was the Jewel Sword!"
Illya stopped being cryptic and explained, "The Jewel Sword can draw mana from countless parallel worlds and can even travel between worlds. Whoever possesses it essentially has an endless supply of mana."
"The Winter Saint Justeaze herself had mastered the Third Magic; she merely lacked mana. If she could obtain the Jewel Sword, she could use that limitless mana to freely wield the Third Magic. With a single thought, she could destroy the world—or open a path to the Root."
"Unfortunately, the Tohsaka family had never managed to forge the Jewel Sword."
"And Jewel Grandpa would never give his Mystic Code to anyone else."
"So both sides had no choice but to settle for the next best thing, using a tiny fraction of the Jewel Sword's principles to construct the Greater Holy Grail system, which could extract leyline spiritual energy and convert it into mana with extreme efficiency."
"I was originally prepared as the Lesser Grail for this Holy Grail War, so when Acht implanted the Holy Grail's information into me, he also infused me with this portion of Justeaze's memories. Those memories included an image of the Jewel Sword."
"..."
The moonlight was bright. Since the Tohsaka family had limited rooms, Illya had no choice but to reluctantly share a room with Little Black and Artoria. Although that made it inconvenient to have Little Black replenish her mana, well... it was totally worth it!
However, less than five kilometers from the Tohsaka residence, Sakura Matou—who had just displayed astonishing power and nearly fought four opponents alone—was suffering inhuman abuse in the Matou family home.
Smack—
Matou Shinji delivered a heavy slap