What is magic replenishment?
In the world of mysticism, it's the most common way to restore magical energy.
There are certainly other methods, but none as effective as exchanging bodily fluids.
"Hey! Have you been secretly reading indecent magazines?" Rias asked lazily, leaning against the table. Her cheeks were burning red, but her brilliant eyes gleamed with something unreadable as they locked onto Kai's.
"What are you talking about? Weren't you the one who suggested it in the first place?" Kai replied with righteous indignation.
If it's handed to you on a silver platter, why not take it? Who's disrespecting who here?
That said, he had to admit—magic replenishment really worked. His mana reserves were nearly full again.
"Ara-ara… I hope I'm not interrupting anything?"
A tall, slender girl had appeared at the entrance to the library without anyone noticing. Her waist-length hair was tied back in a ponytail, and she radiated the elegance of a Yamato Nadeshiko—an ideal of refined Japanese femininity.
In terms of beauty, she was easily Rias's equal, though in her own distinct way.
"Akeno?! When did you get here?" Rias stiffened slightly.
It had been her first kiss. And even though it was just Akeno Himejima who saw it, the moment still felt awkward.
"Wasn't I waiting outside long enough?" Akeno's eyes narrowed slightly as her gaze slid over both of them. A subtle, enigmatic smile played on her lips.
"If she wants to watch, let her," Kai said bluntly. "I'm still short on mana for a full recovery."
With that, he leaned toward Rias again.
"President Rias, did you already give him the item?" Akeno finally snapped, unable to stay silent.
What the hell was going on?
Since when had Kai become so shameless?
Not that she minded waiting a little longer.
But when you're being force-fed dog food this blatantly, it's hard to keep your cool.
(Translator's note: "Dog food" is a Chinese internet slang term for a public display of affection that makes single people feel envious or uncomfortable.)
"Ahem. Yes, we do have more pressing matters to handle," Rias coughed, quickly regaining her usual composed grace.
She raised a hand, and a pale violet magic circle flared briefly in the air before vanishing.
A chessboard with a set of pieces appeared in her palm.
"Pieces of Evil?" Kai's eyes lit up.
This system had been developed by the current Beelzebub—one of the Four Great Demon Lords—as a way to strengthen and expand the number of devils.
It was a technique that allowed other beings to be reincarnated as devils.
"Here. From now on, this Evil Piece set belongs to you."
"Thanks," Kai said without hesitation, taking the pieces.
Rias smiled and added a warning. "Each set has a limited number of pieces. Choose your servants carefully."
"It's best to target rare races or those with Sacred Gears."
After giving him a few more explanations, Rias and Akeno left the library.
"Servants, huh?" Kai turned one of the pieces in his hand but didn't think too much of it.
If this had been before...
He definitely would've started planning how to use the Evil Pieces to build the strongest possible team.
But now? His top priority was his own strength.
He focused, and a familiar virtual panel appeared in his mind's eye.
[Notification: Source +10]
Kai froze for a moment, then glanced down at the intricate magical patterns etched into the Evil Pieces.
"So that's it. That's how I earn Source Points?"
What was the Source? It was said to be the very foundation of reality.
Everything in existence—even knowledge itself—was tied to it.
"No wonder I had so many Source Points from the start. It must've come from everything I've seen and heard over the years."
Testing a theory, Kai grabbed a random book off the shelf and flipped through it quickly.
He skimmed ten lines at a time, and when he finally finished the book, a new notification popped up.
[Source +1]
Kai stared at the floating text and muttered thoughtfully, "So the amount of Source varies. Looks like supernatural content gives more."
He returned the book to its place and sat back down.
With a wave of his hand, a magic circle shimmered in the air.
There was a soft rustle as a cascade of books fell onto the table.
All of them had come from the Underworld—each one rare and valuable in its own way.
Rias had practically forced them on him, hoping to help him increase his strength.
But in his rush to grow stronger, Kai had only studied Lightning Magic, ignoring most of the other tomes.
Until now.
Grabbing the nearest book, he began flipping through it rapidly.
[Notification: Source +3]
[Notification: Source +5]
He hadn't even finished reading it when the notifications began popping up one after another.
"Thought so. My theory was right." Kai's eyes sparkled as he flipped pages faster and faster.
Fortunately, he was a devil now—his memory far exceeded human limits.
Before long—
One book down.
And then—
Kai didn't rush to allocate the Source Points just yet. Instead, he grabbed another book and dove in.
With every page he turned, the Source Point total rose steadily. That's when he noticed something else:
It didn't matter if he understood the content. Just seeing it was enough to gain Source.
Time slipped by.
Night fell deep and silent.
Kai remained in the library, completely immersed, not feeling the slightest trace of fatigue—as if time itself had lost meaning.
"...That's enough for now," he murmured at last, setting a book aside and summoning the virtual panel once more.
[Kai]
[Class: Source Mage]
[Magic: Lightning Magic LV41 (+)]
[Source: 1,815 points]
He rubbed his tired eyes and, with a thought, began distributing points.
Flash. Flash. Flash.
Brilliant light flared again and again across the virtual interface.
Inside him, his mana surged like a raging storm.
It felt like the very air around him transformed into a kingdom of thunder—everywhere he looked, lightning flashed and sparked.
Finally—
The light began to fade.
[Kai]
[Class: Source Mage]
[Magic: Lightning Magic LV60 (+)]
[Source: 1,182 points]
…
Kai focused on the panel and spotted a new notification:
[Ding! Lightning Magic has reached Level 60. Would you like to spend 1000 Source Points to advance your class?]