There's no doubt that the book, gleaming like starlight, is the reason Zuo Si crossed into this magical world and the key to his survival in such a brutal environment.
He didn't know who the previous owner of the book was or how they died.
However, it was certain that this book was crafted by a planeswalker on the brink of death, using the last spark of their magical power.
Originally, it was just something like a card collection album, but once activated, it transformed into its current form.
It wasn't a "system" but rather a tool that expressed itself in a way most comprehensible to its holder.
Within its heavy pages were stored all the cards and possessions created by the planeswalker during their lifetime.
Every time Zuo Si completed a guidance task, he would earn a chance to draw a card, each of varying type and level.
The spells [Mimic] and [mental Library] were rewards from the first and second completed tasks, respectively.
"Finally, my mana pool is about to be full! It wasn't easy, but now I can create my first land card." Zuo Si's voice was filled with unconcealed excitement.
After repeated attempts, he had come to understand that there were three common methods to acquire mana.
The first was obvious: gradually absorbing it from the surrounding environment.
The benefit of this method was that it didn't require much thought; the amount of mana collected was based on the caster's class level.
For example, in this magical world, Zuo Si had attained a creator class level of LV5 through [Mimic], which meant that after a full day of rest, he could gain at least 5 points of general mana.
If his main attribute—Intelligence—was high, he would even get additional bonuses.
As long as he didn't use class-specific abilities or consume mana to brew potions or craft magical items, he could store all his unused mana in his mana pool by the end of the day.
Additionally, each day he could also obtain a portion of energy from the mage tower's allocations to every apprentice.
If he didn't use it all that day, it could be stored in the mana pool.
This stored mana could be used to craft or utilize planeswalker cards, or invested like experience points into a profession to increase its level.
The second method was absorbing the mana of living beings he killed.
After all, this was a magical world—every being, even ordinary humans, carried a small amount of magical energy within their bodies.
Those with professions like warriors or spellcasters, or magical creatures, had exponentially more mana than ordinary people.
At the moment of death, their magical and life energies would begin to dissipate.
As long as he was close enough, Zuo Si could absorb a small amount of the remaining energy.
Of course, the best results came from direct physical contact.
The magical energy would be stored in his mana pool, while the life energy would accumulate slowly in his body, eventually converting into points for his six basic attributes when reaching a critical threshold.
So far, most of these points had boosted his Strength, Agility, and Constitution, while the more useful attributes, such as Perception and Intelligence, were barely affected.
Some of the exaggerated bonuses to Zuo Si's base attributes had come from nearly two years of dissecting living beings under the necromancer's orders.
With his current knowledge of human and other humanoid anatomy, Zuo Si could undoubtedly work as a lead surgeon in the modern world.
The third method, of course, was to use his creator class's special ability—[Refinement].
This allowed him to extract the magical energy contained in potions, magical items, weapons, armor, and artifacts.
However, this usually meant that the item would be destroyed, making it a wasteful and desperate measure.
Unless he was in a life-threatening situation, Zuo Si would never resort to this.
Then there was the "land card," which was a fourth method of gathering mana and the most stable one.
Through the planeswalker's spark, it created a permanent mana conduit linked to him.
This connection couldn't be severed by any power, enabling an endless flow of mana into his mana pool, even across planes, crystal spheres, and universes.
In other words, only a planeswalker with a land card could be considered a true planeswalker.
In fact, Zuo Si had long wanted to create a land card.
The problem was that crafting a land card was much more difficult than crafting other cards.
First, even the lowest-grade land card required at least 100 general mana points in the mana pool, or double that amount in specific colored mana.
This required Zuo Si to advance his planeswalker class to level two.
At level one, his mana pool cap was only 50 points.
Previously, Zuo Si had been using his abilities too frequently to save up much mana.
It wasn't until the plague outbreak, where bodies piled up throughout the mage tower and the floating city, that he finally accumulated enough mana.
Additionally, crafting a land card would create a large commotion.
Zuo Si had no desire for anyone to discover the secret he had worked so hard to conceal.
Even the necromancer Archmage Asta, who had pulled Zuo Si out of that unknown dimension and signed a pact with him, only believed that Zuo Si had some rare "talent."
Asta didn't know that Zuo Si was actually a newly sparked planeswalker from another world, nor did he know that a planeswalker's spark could be stolen.
Otherwise…
Who knows what the cruel and power-hungry Asta, obsessed with attaining immortality, might do.
To better control Zuo Si, Asta had deliberately guided him into the rare and peculiar creator profession when teaching him magic.
His goal was to ensure Zuo Si lost his ability to cast offensive spells, so he would never pose a threat and would always remain under Asta's control.
After all, creators, while skilled at crafting magical items and using scrolls, were ultimately support-focused and lacked combat prowess.
No one with the potential to be a mage would willingly give up spellcasting to become a support tool.
If it weren't for the hidden planeswalker card system, Zuo Si would have long been at Asta's mercy.
Although they appeared to be master and disciple, even allies on the surface, beneath it, they had tested each other many times.
Fortunately, Zuo Si had never fully trusted Asta, remaining cautious all along.
He secretly learned magic and crafted weapons and artifacts while plotting his escape through a portal into Faerûn at the right moment.
But everything had been interrupted by the outbreak of the plague.
Now, Zuo Si's goal was to quickly create a land card and bind it to his creator profession.
Then, using all available resources, he would break through the defensive constructs and monstrous guards, reach the room containing the portal, activate it, and escape the doomed floating city.
Ideally, he would escape to a safer magical world.
For example, he dreamed of hiding out in a magical version of Earth, like the one in the Harry Potter stories, until his body matured.
In fact, the reason Zuo Si had ended up in this situation was rooted in the moment he first ignited his planeswalker spark.
For some reason, his spark resonated violently with the remnants of another spark contained in the legacy artifact.
He was immediately pulled into an unknown space.
Upon touching a mass of gray mist, his body rapidly de-aged from an adult to a child of barely ten years old.
If it hadn't been for Asta's timely detection and transportation of him into this world, he might have continued to regress, possibly into an infant, a fertilized egg, or simply disappeared altogether.
Unfortunately, his plan to hide in the Harry Potter world until adulthood could never come to fruition.
It was impossible to recalibrate the portal's coordinates in such a short time.
It would take days, weeks, or even months of investigation to determine its new location.
Otherwise, if he activated the portal blindly, who knew where he'd end up?
If it was a freezing, airless void of outer space, he would die instantly.
Zuo Si suspected that his unstable teleportation abilities were linked to that strange resonance.
Normally, a planeswalker should only have one spark, but Zuo Si had two.
He had even tried to open a portal to Earth, but there was no response.
This meant that the universe where Earth existed was entirely devoid of magical energy.
Yet, if that were true, how had the legacy artifact ended up on Earth, where Zuo Si had purchased it as a mere craft item?
And how had he entered that strange space after igniting his spark?
Too many questions haunted Zuo Si, leaving him unable to uncover the truth.