Each stage Core condensation involves doubling the size of the core. For example, if the core in the early stage was formed from a thousand drops of liquid spirit qi then the core in the mid stage would have to double its size and reach two thousand drops of liquid spirit qi.

Subsequently, in the late stage, it would double again to reach four thousand drops and then finally eight thousand in the peak stage of the core condensation realm. The amount of spirit qi drops was not the same for everyone and depended on the size of their dantian.

The cultivators that were more talented had higher capacity, while those that were less talented had lesser capacity. Any cultivator that reached the core condensation realm could live for a total of three hundred years.

The next realm after the core condensation realm was called as the nascent soul realm and was the first big demarcation between cultivators. Only after a cultivator reached the nascent soul realm, could he be called an expert.

Reaching the nascent soul realm was incredibly difficult, as a cultivator had to overcome the heavenly tribulation.

When a cultivator reached the absolute peak of the core condensation realm, they would start to get an idea of when their heavenly tribulation would be coming. During this period they were called as pseudo nascent soul realm cultivators as their understanding of the spirit qi had exceeded that of a normal cultivator and were close to that of a nascent soul realm cultivator.

A cultivator would usually suppress the heavenly tribulation until he or she found a proper opportunity. One needed a lot of preparation if they wanted to reach the nascent soul realm as the heavenly tribulation could very easily kill them if they were not careful and well prepared.

Once the cultivator became ready to undergo the heavenly tribulation, tribulation clouds would gather and heavenly lightning would strike their body. The goal of the cultivator was to endure this heavenly lightning and use it to hatch their nascent soul.

Their core would act as the egg, and from it, the nascent soul would be born. Once the nascent soul was successfully born, the cultivator was said to have successfully reached the first stage of the nascent soul realm.

The first stage was called as the infant soul stage as the nascent soul was in the form of an infant. This infant would look the same as the cultivator when they were of that age.

There were three more stages in the nascent soul realm, which were the child soul, adolescent soul, and adult soul stages, for a total of four stages.

The cultivator would be able to freely able to wield the spirit qi in the environment and would have to nourish his or her nascent soul in order to make it grow and reach the next stage. It was also this stage during which the appearance of a cultivator was fixed.

If a cultivator reached the adult stage of the nascent soul realm at the age of twenty, his appearance would be fixed at that age until he reaches the very end of his or her lifespan. At that point, they would rapidly age hundreds of years in the span of a few minutes and then die.

Reaching the nascent soul realm increased the cultivator's life span to a thousand years and made them worthy of starting their own cultivation sects.

Till this point, Lin Wu had known of the cultivation stages and had heard of them before, but the ones that came after this was rather unknown to him.

"The Dao shell realm and the Dao treading realm… interesting." Lin Wu muttered to himself.

The next stage after the nascent soul realm was the Dao shell realm, in which a cultivator needed to form a container inside their dantian. This container was called as the Dao Shell and it was within this that a Dao embryo would be nourished. Reaching this realm increased the cultivator's lifespan to two thousand years.

The sub stages in the Dao Shell realm were the Shell initiation, Shell genesis, Shell completion and Shell expansion. A cultivator could actually skip the final stage, which was the Shell expansion stage and directly proceed to the Dao treading realm if they wanted to, but there were seldom any cultivators that did it.

The main aim to form a Dao Shell was for the growth of a Dao embryo. The larger the Dao shell was, the stronger the Dao embryo that could be formed.

A Dao embryo was nothing but the initial understanding of the Dao of heaven and earth. It could be of anything that the cultivator was able to grasp, and there could even be more than one. But to reach the Dao treading realm, only one shell was required.

If the cultivator wanted to grow more Dao embryos, they had to grow more Dao shell's in their dantian. But this was an immensely difficult task, and most cultivators would only grow a single Embryo.

When the Dao Embryo finally starts to grow, a cultivator would break through to the Dao treading realm and their lifespan would further extend to three thousand years.

According to the record that Lin Wu was reading, this was the highest realm a cultivator from this world could reach.

But there was another realm above this, which was actually familiar to Lin Wu. It was the Immortal Ascension realm. The method to progress to the immortal Ascension realm was not mentioned in the records, and it was stated that each cultivator would have to devise their own method to reach it.

There was no set method, and everything depended on their own comprehension. There was also no mention of how much the life span of a cultivator was once they reached the immortal Ascension realm and none of the current Immortal Ascension realm experts mentioned this either.

'Hmm, this is as complex as I thought it would be, but there are far more uncertainties than I expected.' Lin Wu thought to himself.