Exponential Growth

Filled with excitement, Jack couldn't wait to continue cultivating, but he was also a cautious man and, as such, understood that he could only cultivate during night-time in order to avoid arousing any suspicion. To be seen was tantamount to putting himself directly in the limelight; and for an assassin, the limelight was the worst place to put yourself in. Furthermore, a part of him still didn't wholly trust Ichabod and the rest of the people living and working for him.

This was not to Jack's fault, as he'd spent several thousand years in what was, effectively, constant turmoil; always looking over his shoulder, at any time death could come at the Abyssal Planes and at any moment could one face the charge of hundreds of enemies hell-bent on destroying you. It was only natural that, despite having accepted Ichabod as a foster father, he would still behave cautiously regarding the Harmony of Everything.

Greed is a pervasive emotion in human interactions. Many are the once close families that are split apart due to inheritance. Jack wasn't about to risk exposure and eventual death; not after having suffered all those years of pain and anguish. The Harmony of Everything was a cultivation method that would even make Gods' mouths water at the thought of possessing it, after all.

Thus, Jack played the role of a baby faithfully.

The day passed relatively quickly and nothing worth mentioning happened. He was mostly left to himself, but Adras and Ichabod both came to check up on him and see that the servants were doing a good job taking care of Jack's needs. Jack spent most of the day meditating and recovering his energy from the previous night's cultivation and no one noticed the changes on his body; which had been a slight concern of his, and he'd even considered different methods of concealing it were his finger to be discovered.

However, reality proved that his worries had been for nothing. Perhaps it was that the level of martial prowess of the region he was in was far too low for anyone to detect the change in his cultivation. Maybe no one had thought of checking a baby, as it would be a preposterous thought. Whatever the case, it worked to his advantage.

At nightfall, Jack once again began cultivating his body.

He experienced the same agonising pain as the night before; but he also noticed that with the increase of his soul power, he could double the surface affected by the energy filtered by the ring. In other words, he was twice as successful as the previous night and was able to transform the flesh of two of his fingers before he had to stop.

After that, he entered the ring again but this time didn't hear the dragon's voice. Nor did he see any glimmer of life within its eyes. However, he remained unperturbed and continued with his journey through the pitch black flames within the dragon's body; a part of his mind constantly examining the changes in his soul and prepared to leave should he detect even the slightest hint of foul play. On this night, he was only able to advance another thirty metres before the weight of the flames became too much for him to handle.

And like that, Jack entered into a routine. During the day, he would act according to his status as an infant; even though that had the inconvenience of him having to weep and excrete on himself from time to time. Every night, he would engage in body cultivation followed by cultivating his soul; both in accordance to the Harmony of Everything; and with every night, he would grow stronger and stronger.

After a month, he had been able to completely change his flesh to the point that a fully grown adult without any cultivation wouldn't be able to leave a mark if they struck at him with a knife using their full strength.

After another two months he was able to strengthen his muscles and was able to lift fifty kilograms of weight even with the body of a one-year-old child (he hadn't been able to test this as he hadn't had the chance, but he fully intended to as soon as the opportunity arose).

After another month his tendons had changed to become more elastic and flexible whilst maintaining a level of resistance many would find unbelievable if they appeared on a fully-grown man.

It took him until his second birthday to finish strengthening his bones; much slower than the previous stages.

Jack deduced that the internal aspect of body cultivation represented a formal increase in the difficulty of the cultivation method and so it took him much longer to achieve a minor success with it. However, after he crossed this threshold, his body experienced a qualitative transformation in its overall performance.

One night, he was able to sneak out of the Wishful Hare without anyone noticing. An added advantage of the increase in radius he could extend his spiritual sense was the fact that he could use the sneaking techniques he'd learned in life with an effectiveness that would make any connoisseur sweat bullets. Away from prying eyes, he tested the limits of his body.

To his surprise, he was capable of lifting things of one hundred kilograms in weight without relying on qi; in other words, the natural strength of his two-year old body was enough to leave most adults staggered and with their mouths agape. He could leap two metres into the air and he could dash with breath-taking explosive speed. The only problem was that due to him being cooped up inside the Wishful Hare all the time, he hadn't been able to grow used to his new body whilst performing his techniques and so there were quite a few technical errors in his movements, even whilst practicing the simplest of strikes.

As such, after his second birthday, Jack added another exercise to his cultivation routine, namely the practicing of techniques to get used to the changes in his body and ultimately be able to use it more effectively. However, his outdoor training sessions were seldom and far-between as he couldn't always leave his room. If he were found missing, it would cause an uproar. Therefore, this aspect of his training was lacking, to say the least.

Like that, another four months passed until Jack was able to strengthen his internal organs. That said, his speed of advancement could not be considered slow in the least. Burdened by an infant body, the changes of his physiognomy couldn't be rushed and needed to be performed with the due diligence.

Furthermore, the gains he received from this round of strengthening couldn't just be measured with the power his body could exert. His endurance had gone up immensely, as well as the amount of qi he could draw into his body with every breath. In addition, his mind could work as if it was in overdrive; his thoughts going at a speed comparable to a true supercomputer.

What came next was the strengthening of the meridians, but this proved to be extremely challenging, and the slowest step in his cultivation so far. Just the breaking down of his meridians was a process that was ten times more painful than anything Jack had ever experienced. It was as if they were being sliced open by a red-hot blade over and over again and then having them submerged in a vat of acid. This part of cultivation required him to completely destroy and cripple his meridians before beginning to reforge them; this meant that he experienced no ounce of comfortable healing or blissful reconstruction, only pain.

In addition, whilst he was undergoing this process, it was as if he had become a martial cripple. In other words, he couldn't make the qi flow through his meridians. Whereas this would fill ordinary people with dread, Jack understood that the benefits he would receive in exchange for this temporary state of his meridians would be heaven-defying. Furthermore, the strength of his body was enough for him to survive even without the support of his family.

That being said, the process was a long and arduous one, filled with terrifying pain at every step. Night after night he would put himself through this torture and have his meridians slowly melted down. Even by the time his third birthday had come and gone he still hadn't been able to completely destroy his meridians; the arduousness of the process could be imagined.

In the meantime, his soul power had grown by leaps and bounds; to the point that he could now easily traverse two kilometres inside the dragon's body. Although this was still far from crossing the dragon itself, it was the required level of soul power to begin cultivating the first chapter of the Harmony of Everything.

His overall strength had grown exponentially in the last two years.