Every few days, Leo would prick him with needles and draw blood, and would even collect his fur, flesh, and tissue.
Sometimes, when faced with difficulties, Leo would capture a few Gulu Beast, dissect them, and extract a fragment of an organ, striving to perfect his experiments while ensuring their survival as much as possible.
"So that's how it is. When the cells of the Goddess of Darkness reach a certain level of activity, they become aggressive, devouring surrounding weaker cells and replacing them for growth."
In the petri dish, the blood of the Gulu Beast, which accounted for the largest share, was completely consumed by the Goddess of Darkness's blood, which accounted for only one percent, within a single day.
"So, as long as the Gulu Beast are fused with the blood of the Goddess of Darkness, it will superficially change their life essence. If the dosage is right, they can definitely advance to level two, or even level three."
Leo did not rashly inject it directly. The Goddess of Darkness's powerful devouring ability might devour the entire Gulu Beast. In that case, not only would it not change the essence of life, but even the Gulu Beast would not survive.
In other petri dishes, Leo also cultured a number of Gulu Beast tissues and organs.
These internal organs and flesh were all slowly cultivated by Leo from small pieces taken from different Gulu Beast.
For ordinary life forms, the loss of even a small organ can have serious consequences, but for Level 1 life forms, given enough time, their powerful life force can allow the missing organ to regrow.
The blood of the Goddess of Darkness was first injected into these organs. As long as these organs could withstand the blood's absorption, the next step would be to conduct live experiments.
Unfortunately, Leo's organs died less than half a day after he received the Goddess of Darkness's blood.
The cause of death was not the absorption of the Goddess of Darkness's blood, but rather the over-evolved cells that burst the organs, causing them to fail prematurely and die.
After more than fifty organ injection experiments, Leo finally found the problem.
The cells of the Goddess of Darkness do indeed have the ability to engulf other cells. After being injected into an organ in a culture dish, the cells of the Goddess of Darkness will immediately engulf all other cells of the same kind.
However, once the Goddess of Darkness cells take over an organ and achieve dominance, they will stop devouring and begin to modify the organ to adapt it for their own survival.
These cells seem to have their own consciousness, knowing what they should and shouldn't consume.
They are like the most wicked thieves, killing their master, occupying his house, and then remodeling it to their own comfort.
Unfortunately, these houses simply couldn't withstand their abuse; their fragile organs collapsed.
"The organs of these Level 1 Gulu Beast have a fatal constraint; their evolution has been capped, and once that cap is reached, they will collapse."
Of Leo's fifty experiments, forty-three lasted only half a day, while the remaining seven lasted a full day.
Therefore, organs that can only sustain life for half a day are at most at level one peak, while organs that can sustain life for a whole day are at level two at their maximum.
This is not an accurate data analysis, but merely Leo's rough guess.
To verify his hypothesis, Leo brought Benji onto the operating table.
"Don't be afraid, I just need to take some organ samples. With your level three strength, you'll recover in no time."
Benji knew Leo wouldn't harm him, but seeing the sharp scalpel slice through his skin still sent chills down his spine.
Once Leo successfully cultured the Benji organ, he immediately injected it with the blood of the Goddess of Darkness.
This experiment lasted for three full days before the organ finally collapsed due to over-evolution.
When an organ fails, its energy activity level is more than three times higher than it was three days prior.
"What is certain is that the cells of the Goddess of Darkness possess the ability to enhance the essence of life, but it's simply too powerful."
"Even Benji's excised organs couldn't withstand it. It's incredible that the first Gulu Beast to be infected and have its life essence altered. I wonder how it survived when faced with such highly active cells."
Leo kept making notes in his experimental notebook, and couldn't help but admire the earliest Gulu Beast whose life essence was altered.
Now, even cells that have been dead for over a thousand years are beyond the capacity of Benji and his people to withstand. How did the Goddess of Darkness manage to survive without collapsing, when she was still alive?
"We also need to find a way to reduce the activity of the Goddess of Darkness cells."
Leo already had some initial ideas about this.
New blood cells are extracted from the already collapsed organs and injected into other organs.
In principle, cell activity is fixed. These cells of the Goddess of Darkness have already destroyed an organ, so their activity must be weakened.
Furthermore, it also contains Benji cells, which further reduces the concentration of Goddess of Darkness cells.
With several generations of culture, it is certain that fully adaptable living cells can be cultured.
As long as the approach is correct, the experiment is not difficult at all. After three generations of culture, the new organ showed no signs of collapse for a month.
Although organ activity and energy intensity were only 1.5 times higher than before, this meant that Leo's experiment was successful, and he successfully reduced the activity of the Goddess of Darkness cells!
Improving the life essence of a race is not something that can be achieved overnight; it requires generations of cultivation and continuous human intervention.
Only through generations can the best individuals emerge!
After all, it has changed the life level of this generation, and it is unknown whether it can be passed on to the next generation. The blood of the Goddess of Darkness is limited, and it is impossible to cultivate them one by one.
Only when they pass on this excellent life essence to the next generation can we be considered successful!
Three years later, Leo could say with certainty that this generation of life essence enhancement drugs had been born.
The first injection was given to Benji!!
Leo told him, "I'm 90% confident that after receiving this injection, your size will exceed forty meters. As for the remaining 10%, there's a possibility of rejection, causing functional disorders and a significant reduction in strength."
"Lord Leo, I believe you."
Without Leo lifting a finger, Benji injected the drug into his body himself.
There was no rejection reaction, and in just one month, Benji's body grew by one meter.
This was the first time in over a hundred years that Benji had felt an increase in strength, and his physical body was still evolving at the same rate, with Heavenly Capital.
With every breath, the body undergoes a complete transformation!
Although Benji consumed a large amount of high-energy food during this process, his ultimate success led Benji to kneel devoutly before Leo, worshipping Leo as if he were a god. He pledged allegiance to Leo with the Wizard Will, leading his entire tribe to do so—a devotion to which they offered their very souls.
Even if Leo asked Benji to die right now, Benji wouldn't hesitate.
The remaining 110 Level 1 Gulu Beast were not injected immediately, but waited to see if there were any further adverse reactions from Benji.
The result was surprisingly good; there was absolutely no rejection reaction, and not a single one of the symptoms that Leo had theoretically deduced appeared.
Leo pondered why things had gone so smoothly, then suddenly slapped his forehead and remembered that Benji and his group of Gulu Beast had already been infected by the Goddess of Darkness, meaning they no longer rejected the Goddess of Darkness's cells.
The current fusion is merely an awakening of the genetic inheritance deep within the memory. As long as it is within the body's tolerance, then everything will be fine.
Thinking of this, Leo didn't know whether to laugh or cry, because raising the life level of the Gulu Beast Clan was much easier than he had imagined, but it also meant that Leo's attempt to use the same method to raise the life level of other races was completely futile.
Unless Leo can uncover the powerful figures among their ancestors, purify their ancestor's cells, and integrate them into their bodies.
Stealing the corpse of a Goddess of Darkness was already incredibly lucky; Leo wanted to slap himself for even dreaming of replicating that luck.
Knowing that there would be no rejection reaction, Leo immediately injected the remaining level-one Gulu Beast.
Although he already knew the outcome, Leo still observed for a month, and indeed, just as he had predicted, each of the Gulu Beast had become significantly stronger.
While the increase in strength may not seem to be the kind that makes someone a god in a day or a god in two, the hierarchical constraints they originally set in their lives have been broken without them even realizing it.
The Gulu Beast was originally destined to only become a Level 1 life form, now has the potential to become a Level 2 life form.
Of course, injecting the drug doesn't guarantee a Level 2 certification; it just increases the possibility, and their future efforts will also play a role.
"You must strive to produce offspring. Whether you can change the very nature of your race depends on the qualities of your descendants."
At this point, we can only say that the experiment has just completed its first small step. Only if such a high level of life can be maintained for several generations can the experiment be considered successful.
Reproduction is destined to be a long experimental process!
"I will urge them on," Benji assured him, more concerned than anyone else about the advancement of the entire race.
"You'll have to go yourself. Your genes are better, so you might get some unexpected results." Leo gave Benji a mischievous smile.
"..."
Benji!
In order to enable them to reproduce, Leo even specially designated a place on the first floor for them to live in.
The violent elemental energy of the Tower of Elements is unsuitable for newborn infants. Only within the Wizard's Tower, under its protection, can the elemental energy subside, allowing the newborn to grow healthily.
With everything settled, Leo stopped worrying about the reproduction of the Gulu Beast Clan. There were still less than sixty years until the next expedition, and judging by the Gulu Clan's reproduction rate, they should be able to see the third generation soon.
We'll know whether the experiment was successful by then!