Mr. S was an anonymous person Will had met through a request he posted to the Adventurer's Association a year ago.
At the time, Yiel was learning to master her Ice Armor ability. Will calculated its theoretical limits and found it could withstand 200 degrees Celsius, but Yiel still suffered burns during training. Unsure how to fix the issue, he posted a request for advice.
That's when he received a letter signed only with the initial S.
The letter detailed the principles of Ice Armor and explained why Yiel was getting burned. One key insight was that Ice Armor worked by dynamically melting and regenerating, which created gaps in its defense. When exposed to extremely hot steam, the ice could vaporize, and the higher temperature of steam compared to liquid water made burns more likely.
S's solution was simple: create an air gap between Yiel's body and the Ice Armor. This way, the armor could cool the steam into liquid or solid ice before it reached her skin. By integrating this gap into the dynamic regeneration cycle, burns could be avoided altogether.
Will tested the theory, calculated the ideal gap distance, and had Yiel try it. It worked—no more burns.
This was a turning point for Will. He realized that the numerical calculations he had created for game design could be applied to real combat in this world. His years of memorizing formulas and writing equations had finally paid off.
S was equally impressed with Will's detailed calculations, and their correspondence grew. Over the years, they exchanged letters discussing dungeon monsters, magic compositions, and weapon techniques. These letters piled up in Will's cabinets, turning into a treasure trove of knowledge. He joked that if he ever pursued graduate studies at a magic academy, he could write dozens of papers just from these exchanges.
Initially, Will referred to S as "that S," but over time, S became "Mr. S."
S had never revealed their gender, but Will assumed they were a man. The letters were logical, concise, and filled with practical advice—traits Will associated with a reliable, battle-hardened adult male.
But there was a bigger question: Who is S?
This was a novel world, so someone as skilled as S must have appeared in the original story. Yet, no professors at the magic academy fit S's profile—they were mostly theoretical experts with little practical experience.
What about adventurers? Most adventurers specialized in their fields and lacked the broad knowledge S possessed.
Could S be… the protagonist?
In the original story, the protagonist, Hugh, was exceptionally skilled in theory and knew the ins and outs of multiple professions. But Will dismissed the idea after rereading the timeline. At this point in the story, Hugh was still in school and hadn't started dungeon adventuring yet.
Will tested this theory in a letter, asking S about their background. S replied that they did occasional logistical work for adventurers and had practical experience from helping on shallow dungeon floors. They even offered to assist Will with materials if needed.
The timeline and behavior didn't match the protagonist. Will sighed with relief.
"Probably just a hidden expert," he thought. "Stories like this always have mysterious hermits who never get named or appear in the spotlight."
Still, Will couldn't help but feel disappointed. If S had been the protagonist, they would've been like a mentor, providing endless support and advice.
"Too bad," he muttered. "Mr. S will remain anonymous, and I'll likely never meet them."
"Let's see what Mr. S sent this time," Will said, holding a package under the warm glow of his desk lamp.
Inside, he found a letter, a small wooden box, and a tattered, yellowed book.
Will opened the letter first:
**[To: W,
Last time, we discussed restoring the ancient magic spell "Extreme Flame Meteor." Unfortunately, ancient magic isn't my area of expertise, so I can't help much. However, I found some relevant records in an old dungeon book.
One passage mentions a required medium: the stomach lining of a small monster called the Explosive Firefly. I hunted over 100 of them and extracted a small bottle of the substance for you. It's included in this package—use it sparingly.
If you can gather precise data on explosions and damage during testing, please share them in your next letter.
S]**
Will opened the wooden box. Inside, nestled among earthquake-resistant packing materials, was a tiny vial of powder. Under the moonlight, it emitted a faint pink glow.
"This could be useful," Will murmured. "But there's no guarantee it'll work."
He flipped open his red-covered Task System notebook and turned to the relevant page.
[Important Task: Have Yiel block the Extreme Flame Meteor. This is essential. Conduct a preliminary test just in case.]
Will's expression grew serious.
The note reminded him of a key plot point from the original story—one that had dire consequences for "Master Will."
In the original novel, Will had been ambushed by a witch wielding the Extreme Flame Meteor spell while traveling to the imperial capital to attend Entak First College.
The attack left him injured and unable to participate in the practical admission exam. This incident caused a domino effect: Will became the target of bullying, developed psychological issues, and his relationship with his father deteriorated. The event also marked the downfall of the popular half-elf princess.
Back then, Will thought the villain deserved such a fate. But now that he had to face it, the prospect was far less amusing.
Blocking the Extreme Flame Meteor was crucial.
Will flipped to the next page of his notebook to check the task's reward:
[Reward: After completing Task 38, unlock Yiel's exclusive ancient magic: Ice Array.]
The Ice Array was a game-changer. It was like giving a basic character a power-up that turned them into a top-tier fighter. However, in the original story, Yiel had only learned Ice Array after becoming a defeated, discarded character.
"What's the point of being a loser T0?" Will grumbled.
If Yiel could master Ice Array early, it might change her fate—and his own.
Determined, Will reopened the tattered book, grabbed some scratch paper, and began taking notes.
As Will scribbled formulas under the flickering lamp, there was a knock at the door.
"Yiel?"
The door creaked open.
"Master… um… aren't you going to bed yet?"