5 months later
Kayden spent his entire fourth year just fighting non-stop in the arena. His day would start with early morning training and then about 10 to 12 hours at school. His progress was insane, he learned how to fight different types of elements.
He still wasn't able to win most duels. Unlike fighting melee fighters, Kayden couldn't use his experience to beat ranks above him. His technique wasn't very useful either, as if he approached, the fight was over, and students usually gave up at the slightest sign of pain. He also hasn't learned any other lightning spells.
He preferred to specialize in the ones he had at the moment. Which proved to be the ideal choice. His Pop Flash was able to be instantly performed anywhere on his body. His mana control allowed him to choose, for example, above his head, so he wouldn't be caught in the light. Another achievement of the boy was being able to use acceleration at full strength, he gained 5% in full body now.
He no longer had imbalance issues, not only that, he was able to alter the technique to cause an overload for a brief moment and achieve 10% additional speed. The concentrated lightning was mixed with his sword for him to be able to deliver a slash at the same time as unleashing lightning. It could be said that Kayden didn't have anything spectacular in his repertoire, but every skill was being utilized to the fullest to be the best effect.
His mana heart was also finally ready to reach 4th rank, the problem was that Heimer was busy training, and Kayden practically never found him at home.
He would go to David, the scientist had already offered his help before, and this time the boy accepted. His relationship with David was very good, a secret capable of causing a continental war was a good bringer of people.
After asking his father's permission, Kayden resumed on a path he hadn't taken in over a year. The trip was strangely the same as usual, it seemed like nothing had changed since he first came two years ago.
When he arrived at the station, Kayden saw David waiting for him. The scientist was still the same, with hair like a mouse's nest and wearing an impeccable white lab coat that didn't match his body.
"Hello, Kayden, come on, hurry up, the taxi is waiting", the scientist could barely stand to test everything he could with Kayden. He didn't even let the boy speak until he got in the car.
"Hi David, how are you?" Kayden tried to talk to the scientist, but the other was too anxious and any talk from him would be about their secret. So he held on until he reached the foot of the mansion.
As soon as the two passed through the door David activated the alarm and security mechanisms of the house. Turning quickly to Kayden, the man said:
"Come on, show everything, cultivate, use mana, everything you can do, I want you to show me", Kayden came ready for that and had already asked to stay here for two weeks.
Your second objective in coming here was to have some real battles against beasts. Only the mock ones were starting to stall his progress, Kayden missing the real danger of a battle.
"I just need to eat first, David," Kayden's stomach rumbled in agreement with his statement.
"I only have leftovers from... someday", the scientist said and this statement caused Kayden to feel déjà vu.
...
The two spent the rest of the day trying out different things with Kayden's heart. Total storage and mana release speed, restoration speed, and how much the body has been fortified.
The tests lasted about three days, and hundreds of data were collected, some strange that Kayden had no idea could exist, such as the speed at which hair grows, his was slightly faster than the average human.
Finally, the day came when he reached the 4th rank, It took a long time if you consider the boy's entire 8 years of life, but if you consider it with a new heart, he went from the 1st to the 4th realm in 1 year, that was completely absurd if compare with the cultivation speed of other children.
Kayden was sitting in the lab at the same experiment table where he had the surgery a year ago.
"David, I need at least 3 or 4 times more mana than a mage of my rank", Kayden repeated to the scientist.
"I know, kid. Do you think I would forget something simple like that?"
Kayden said nothing more and began the process. He felt ready to pass, it was the same feeling as other ranks. Mana began circulating through his heart and veins at an accelerated pace.
Minutes passed and Kayden was still on the same landing. 10 minutes and 2 times more mana used than a normal mage. 20 minutes. 30 minutes and 3 times more mana. The process was still far from over.
Kayden knew it wouldn't be simple this time. Advancement every 3 ranks was a micro-realm advancement. It was a quality difference. Close to 40 minutes, Kayden had already used 4 times the normal mana.
His body was heating up, it felt like he was going to catch fire. His heart was like a drum. The pain came before he could make progress. Kayden bit his teeth and continued.
He had already come too far to give up now. Every second he felt he was closer to breaking through. His body burned more and more. 45 minutes. The pain was unbearable.
When he reached 50 minutes, he used the equivalent of 5 times normal mana. His body heated up to the point where smoke started to come out of his skin. His heart squeezed painfully.
This time, he couldn't even sit still. Kayden dropped to the floor like a rag doll.
"Kayden!?" David was startled and went to hold the boy, his skin was burning to the touch. Still holding the boy, he felt the boy's body begin to progress.
His veins dried up to the last drop of mana. This time, his heart began to transform differently. It felt like it was expanding at an accelerated rate, its mana vessels were also stretched beyond what it was.
His body started to develop the vessels for his legs and they only stopped when they reached his thighs. He had at least a 30% increase in the size of his vessels. This was very gratifying, it was becoming more and more difficult to increase the size of his pots.
Finally, Kayden felt his body stop heating and aching. The process was a success. His veins were smaller and stronger. His heart was able to pump out much more mana than before.
He still hadn't tested his body, but he believed that it was at least at the peak of rank 4 in terms of strength. And if it used acceleration, it could reach the base of the fifth realm for a few seconds.
When the boy came to, he noticed a sour and disgusting smell, it looked like an animal had died at the scene. Looking at his body, he noticed a black goo impregnated on his clothes.
"Go clean up, Kayden. This is the impurity of the advancing process of knights and swordsmen. We'll have to burn the clothes", David explained to the boy with his nose plugged to avoid the stench.
A few minutes later, Kayden returned wearing a new outfit. The boy had to admit that that goo was persistent, he had to rub it several times to get it off. It felt like he would be glued to his body for the rest of his life.
"David, I'm going to take today to stabilize myself in the fourth rank. Tomorrow and the following days, we can carry out the tests", Kayden expressed before the scientist wanted to place him as a lab rat indefinitely.
David agreed and left to do other things of interest. Seeing the man leave, Kayden sighed in relief. He feared that the scientist would confine him. David's excitement was simply unnatural.
Kayden began to farm and watch his gains from this breakthrough. In a matter of hours, he had already theoretically stabilized his rank. Now, there were only a few fights left to effect its stabilization and practical form.
Over the next few days, the two measured various data again. Some had a considerable increase and others did not change at all. After the tests, Kayden was in the lab with David.
"David, can you explain to me the differences between geniuses and normal people? Or talented people? Quantitatively, the same as we did in the tests?"
He had always heard that a genius was worth 10 ordinary people, but how far that was true, the boy had no idea.
"Let's get some lunch, this conversation might be a little long", David was ready to give the boy an expert-level lesson.
The two took a pizza prepared by David from the fridge. Since the boy taught the scientist the process of this delicacy, he practically transformed his diet into something based almost 100% on pizza.