Gru moved quickly. In less than ten days, he brought ten humanoids to Leo.
Humanoids possessed certain human characteristics, and some of their organs were identical to those of humans. They were perfectly suitable for experiments and were among wizards' favorite experimental materials.
"These are slaves I just bought. They've already been registered and recorded, so experiment on them without worrying. If you kill them, tell me, and I'll buy you more."
Leo showed little reaction to Gru's blunt, brutal, cold words, but the ten humanoids trembled uncontrollably like frightened quails when they heard them.
Clearly, they already knew the fate they were about to face!
Leo had long since grown impatient. Over these ten days, he had thoroughly planned the experimental procedures several more times, waiting only for this batch of humanoids to arrive.
After Gru left, Leo gently reassured the ten humanoid slaves. "Don't worry. The experiments aren't as serious as you think. Once you help me complete them, I can apply to have you granted the rights of commoners in the Wizard World."
"What's your name?"
Leo kindly addressed the strongest humanoid among the ten slaves.
These humanoids had much the same body structure as humans, with long limbs and particularly powerful legs. They seemed very good at running. The slight difference in their appearance lay in their ears.
They had overlapping ears, meaning four ears, which undoubtedly gave them excellent hearing.
Leo could roughly sense that these humanoids had around 20 points of attack power, while humans on Earth had around 5.
One such humanoid could fight dozens of Earth humans, yet they still could not escape enslavement by wizards.
"Great wizard, my name is Neven," the humanoid slave answered cautiously.
Leo understood what these humanoids had been through. An unknown number of years ago, their world had been conquered by the Wizard World. Because they had resisted wizard rule, they had all been designated slaves who could be bought and sold freely, a kind of merchandise capable of thought and movement.
Leo did not chat further or even ask what race they belonged to. Test subjects needed to understand their place as test subjects. His claim that there was no danger was merely something he said to secure their cooperation.
Anyone who really believed experiments were harmless was a complete idiot and deserved to die!
The first step in modifying organs was to understand the experimental materials.
Gru had selected the slaves expertly. They included males and females of different ages, allowing for better comparisons.
Undressing, physical examinations, blood draws, energy testing, sensory testing, toxin resistance testing, high-temperature testing, low-temperature testing, internal organ testing...
At the operating table, the sharp scalpel in Leo's hand sliced open the fourth slave's chest, clearly revealing the pulsing organs within. They were indeed seventy percent similar to human organs. Although some differed from those of humans, this would not have much impact on the experimental results.
Leo cut a piece from each internal organ to test its function, then sutured the incision and let the slave enter recovery.
Leo had prepared recovery potions long ago. Surgery like this could heal completely within a few days.
By the time the hundred-plus assorted experimental tests were complete, more than half a year had passed.
After fully understanding the data, Leo would formulate poisons based on their feedback.
Next, Leo gave them weak toxins containing calibrated energy markers to drink, allowing him to better observe how the body's different organs reacted to different toxins.
During this process, three slaves failed to endure the poisoning and died. Four others suffered a decline of over fifty percent in their constitutions. Continuing would have a tremendous impact on the experimental results, so Leo could only find some other use for these four rejects.
Leo had no choice. The remaining three slaves were insufficient to calculate accurate experimental results, so he had Gru buy another ten slaves and began testing and experimenting anew.
With that, another year passed. Four years of his twenty-year assignment guarding Tiyama City had already elapsed.
Two whole years spent inside the laboratory had absolutely been worth the effort. Leo had thoroughly figured out how every organ in these humanoids functioned when faced with toxins, and which toxins each organ detoxified most effectively.
By this point, only four of the twenty slaves Gru had purchased remained.
Their fragile bodies could not withstand the repeated damage from the toxins Leo constantly adjusted. Aside from those who died quickly of poisoning, the remaining few had all developed cancer. Even if the experiments ended now, cancer would torment them for the rest of their lives until they died.
"The experiments show that the body's detoxification organs are unsuitable for modification. A completely opposite function causes rapid organ failure, leading to the test subject's death."
"During the experiments, I discovered by chance that tonsils, which possess the ability to resist toxins, are more suitable for modification."
"The tonsils are part of the immune system. They resist viruses and bacteria, and the lymphocytes they produce can participate in immune responses throughout the body. Most importantly, the tonsils can become infected and turn into harmful organs that endanger the human body."
"Moreover, the tonsils function during childhood. Once adulthood is reached, they serve little purpose."
"During the experiments, ten slaves developed infected tonsils, which continuously attacked their immune systems and weakened their constitutions. Without external intervention, this condition could lead to the slaves' slow deaths."
Leo finished recording his experimental notes and let out a long breath. Although two years of experiments had been exhausting, he had found a direction and the organ most suitable for modification. Nothing could have made him happier.
The experiment's success confirmed his conjecture and, even more, his own significance.
At the moment of success, Leo gained a deeper understanding of what it meant to be a wizard and to master rules!
The feeling of mastering and exploiting rules was simply wonderful, as though everything were in the palm of his hand, giving him the illusion that he was the Creator himself!
"The four of you will be settled in Tiyama City. I know the city lord here, and he will grant you the corresponding rights."
Of twenty slaves, only four had survived. Although they all had cancer and little time left to live, Leo kept his promise and still granted them commoners' rights.
As the four slaves left the laboratory overflowing with gratitude, Leo's experiments entered their second phase: modifying his own tonsils.
First, he needed to infect his tonsils. Once they became harmful organs, he would begin cultivating their toxicity until they finally reached a balance with his body. At that point, the modification experiment would be a complete success!
Infecting the tonsils was the easiest part. Leo already knew which toxin worked best on them; this had been successfully verified on the test subjects long ago.
Lancoxin was a toxin that targeted only the tonsils. Taken continuously for thirty days, it would completely infect them, turning them into harmful organs within the body.
After this step, all he needed to do was cultivate toxins in the tonsils, feeding them various toxins little by little.
Once the tonsils began infecting the body's major systems and could independently absorb toxins to grow, the process would be fully complete!
"Cough, cough."
Because he had failed to get the toxin dosage right, Leo had been laid low by poison. The humanoids' physical makeup still differed from his own, and the experimental data remained uncertain even after adjustments for his body.
He leaned weakly against a bookshelf, his eyes half closed as he pondered something.
Thud, thud, thud.
Heavy footsteps approached. Leo looked up, and Gru's massive body, over two meters tall, filled his vision.
"How's the experiment progressing?" Gru felt Leo's head, which was almost hot enough to burn his hand, then looked at his neck. By now, Leo's neck had swollen so much that it was larger than his head, an extremely bizarre sight.
"A little problem. Nothing serious. It's all under control." Leo's voice was thick and nasal.
The tonsils' growth had exceeded Leo's estimates. He had not expected a benign organ originally belonging to the immune system to develop so quickly after turning into a harmful, malignant organ.
Was this what it meant to be hard to be good, but easy to turn bad?
Gru carefully assessed Leo's condition. There was indeed no major problem, so he turned and left again.
In his dazed state, Leo extended a finger. The shadow beneath his feet twisted and instantly merged into his body, into every limb and bone, into every cell.
He could clearly feel the toxins in his body rapidly transferring into the shadow. The swollen tonsils in his neck shrank at a rate visible to the naked eye.
His fever subsided, strength returned to his body, and his dizzy mind began to clear.
Leo extended a finger, and a pitch-black shadow emerged from it, even making a point of bowing to him in greeting.
The organ modification and toxin growth plan was complete. Now, he only needed his tonsils to return to their original size, which would signify full integration with his body.
Leo could feel the toxins secreted by his tonsils constantly attacking his body. Under their stimulation, the cells within his body were continuously evolving.
The evolution was slow but sustained.
Soon, the shadow had removed fifty percent of the negative conditions in his body, turned back into a shadow, and returned beneath his feet.
Leo felt his neck. Although some swelling remained, it would soon recover.
He took out his experimental notebook. Three experimental projects were recorded at the very front, the first being an experiment on stimulating bodily cell activity with toxins.
With the success of the tonsil modification experiment after three years, the first experimental project had been successfully completed.
The second experiment concerned his Shadow Talent. Leo would not act like Benji and the others, who relied entirely on casual perception, using only as much as they could understand without investigating the essential mysteries within.
Leo planned to study his Shadow Talent next. He knew far too little about this talent that Benji praised so highly.
The abilities demonstrated by the Shadow Talent were indeed powerful. It could absorb negative conditions from his body, store energy, split off tentacles to attack, and even use stored toxins to attack enemies.
That did not even include Shadow Jump and Shadow Space, which Leo used most often.
The abilities his Shadow Talent currently displayed already encompassed offense, defense, support, escape, and space.
If Leo could not figure out such a powerful talent, the frustration would truly make his teeth itch.
He could ask Benji for more information about the Shadow Talent, but Leo knew that Benji certainly could not tell him what he wanted to know.
He was no longer the newbie who had just stepped into the supernatural world and had to accept every bit of experience they imparted without question.