Now, Thor, Harald, Hajrudin, and Loki were standing inside the secure confines of Thor's private laboratory.
The room hummed with the quiet vibration of advanced machinery as the four giants stood transfixed, staring intently at a massive syringe that was displayed prominently on the center table.
With the colossal ship that Thor would use to travel the sea finally being completed, Thor now wanted to finish everything that he had set out to do regarding his family's welfare while staying in the Country of Elbaph.
"What is that, Thor?" Harald asked. He was genuinely curious to know what he had been staring at for the past few minutes.
He directed the question towards Thor as he inspected the strange substance inside the syringe.
It was colored a vibrant cyan but swirled with a tint of ominous purple and a dark, viscous liquid that looked almost alive.
"This is a serum that would directly make our genes, specifically the Ancient Giant genes, purer and stronger. It is a catalyst which would give us the ability to become even more powerful than we are now," Thor said.
He then began to explain exactly how he created this serum. He reminded them of what had happened to his loyal pets, Tanngrisnir and Tanngnjóstr, who were now living comfortably in the giant ship that Thor had created.
The two goats continued to grow and evolve more and more until the process stopped. They had transformed into two majestic goats that had long, flowing hair.
This hair possessed a tensile strength that is much stronger than any normal rope, and they could continuously grow their hair back instantly,l ike it was nothing.
Furthermore, the two also have their physical strength increased by more than a hundred times.
Despite Loki being so much stronger than the goats before, the young prince was now having a harder time trying to beat them in a friendly wrestling fight.
This evolution is only the effect of the pure Eitr. Now, Thor had studied, modified, and perfected it to incorporate it towards a stable serum, with the Eitr acting as a base for the catalyst of evolution.
When Thor tried the serum on a sample of his own DNA, the change was imminent. It directly started rewriting his genetic sequence as the serum introduced the new protein it brought.
The culture that he has from his own genes, with his Lineage Factor already being modified due to eating a Devil Fruit, made an entire generation of new and improved genetic enhancements.
The culture that contained Thor's DNA was covered with ice rapidly. It then began to climb with its freezing powers, to the point where only Thor was able to touch it safely, as he is immune to ice directly.
With this result, as well as countless other tests, Thor is now incredibly confident that he could inject the serum safely.
He was now ready to inject it into Harald, Hajrudin, Loki, and himself to make them even stronger.
Thor then collected blood samples from Harald, Hajrudin, and Loki to create specific serums for them.
This was to ensure that the change fit perfectly with their current physiological state.
With the detailed explanation of Thor, the three understood what Thor had been talking about.
Not only were they surprised by the breakthrough, but they also couldn't help but feel a little bit scared by the terrifying depth of knowledge and the calculating mind of Thor.
"So, who wants to try first?" Thor then asked. This question made Harald look at his three sons.
Loki and Hajrudin were standing closest to him, while Thor stood confidently in front of him. Deciding to trust his son and lead by example, he decided to volunteer first.
"I will become the first test subject then," Harald said towards Thor. Thor then took the massive syringe prepared for Harald.
He stepped forward and then injected Harald with the Eitr Serum. When he did, the reaction was instantaneous. Harald immediately felt a deep chill running through his body.
He then started displaying a bioluminescent blue glow underneath his skin, and his horns and hair started getting visibly longer.
Thor then saw the floor starting to freeze rapidly around the King. Reacting on instinct, Thor created a dome of ice around Harald.
He knew what would happen, and sure enough, Harald released an uncontrolled ice blast that would have frozen the entire laboratory solid if not for Thor's intervention.
When Harald finished glowing, his skin also turned back into its normal tone. However, there is something that Hajrudin, Loki, and Thor had noticed.
Harald now possessed longer horns, with their color being changed from its original dark color into a vibrant cyan color. Harald also started emitting a cold breath that created frost wherever it hit the air.
"I feel strange," Harald couldn't help but comment. Despite not having many noticeable changes in his physique aside from the horns, there is something powerful surging within his body.
"The change is not instant. It would take time. The strangeness you are feeling today is the serum modifying your entire body. When it is finished, you will see what kind of power it really has," Thor said towards Harald, reassuringly.
Both Hajrudin and Loki also voluntarily came towards Thor, as they also wanted to incorporate the change that their father had just experienced.
Seeing this, Thor then injected them, as their process towards evolution started.
Thor also injected himself with the serum, as he had created a specific serum for himself as well.
When they all finished injecting their serums, they all left the laboratory, not knowing that their bodies were starting to change in ways that would shake the world.