By this point Kaleb had been walking the desert for several hours and the sun was just reaching its peak above him. His skin had turned deep red as the sun burnt his flesh since he had no protection from its brutal rays, his days spent locked inside his room were coming back to haunt him. To top it off his clothes were drenched and his throat was parched, he would need to find water soon. He had just crested another dune and paused as he viewed the seemingly endless desert around him.
The news that had so depressed his parasite of a guide had no real impact on Kaleb's mood. There was no magic on Earth; that he knew of at least. Thus the lack of his own magic did not surprise or concern him in the slightest. But when he voiced this to Rackshar he was met with more disdain.
'You fail to understand anything, you slave! I visited your planet, if you don't remember, and I know that it lacks magic! The intelligent truly are the greatest fools. Why must I have been tethered to someone so worthless.' With each sentence Rackshar moved from disdainful to a more self pitying tone.
With a final pathetic sigh he seemed to pull himself together and told Kaleb the wonders of magic. Soon, Kaleb felt he had a decent grasp of the situation after Rackshar's explanation.
Basically the Magic in this World was a constant force that flowed through everything. The rocks, dirt, plants and air all had this flow. Living beings also produced a certain amount of this magic. This inner magic was the energy that was keeping them alive, fueling their existence. Most living creatures produced just enough to accomplish this task.
Some called this ever present energy lifeforce, others called it essence, and others mana, but it was all a description of the same concept. Since the inner magic produced was not usable without burning up lifeforce, magic was used by drawing this energy from all around and giving it shape to then create a physical reaction in the world. Much like electricity itself has very little application in its raw form but can be used to create many different applications when used to power various machines.
The applications of magic were just as varied. Some used it to create elemental spells of varying complexity, like a mage, others used it to strengthen and enhance their bodies and fighting styles, much like cultivators would. Creatures used this method as well, though to various degrees and limited to certain methods based on their intelligence.
Though, this gathering of energy from the air was considered to be the lowest form of magic possible. It was limited based on how much energy one could draw from the air and therefore could only have small applications. To overcome this limitation, magic users would form cores of energy in their bodies.
These cores were created by compressing energy into a single condensed area and giving it an application. Without an application to bind it to one spot, the compressed energy would explosively dissipate due to a lack of an anchor.
If that was all there was to these cores then they would only be useful until they used up the condensed magic, which based on the mana in the core could be as little as one spell, and then they would be gone. What made these cores the foundation of the world was that through compression and a powerful enough application applied, these cores are self generating mana pools.
In that sense a human could be considered a core. They are created using the energy of the world and are given a application, namely the running of the human body. Even though it took external energy to create a human, once it is created, the energy becomes self replicating; or vitality is no longer drawn from the outside to keep a human alive. But, once a human dies, thus losing its application, the energy ceases to generate and the vitality will dissipate.
Cores are the same way, they have to have an anchor of application given to them, namely a spell or ability, and have enough energy condensed into them until they are stable. Though a human body is constantly drawing on its energy to exist, the cores, that are based on a spell, would only use energy when that spell was used and would be able to spend its surplus generated mana to refill its reserve.
But, the cores could only hold a certain amount of energy based on their grade so once it reached that capacity cap it would stop generating. Luckily a core, unlike a human, would not cease to exist if it was completely drained of power, but it could not be used until it replenished enough energy.
The grade of the core was ranked grade 1 through 10 with one being the weakest. Higher grade cores were made by exponentially increasing the energy compressed into it to increase its grade. Also grade 1 cores could only hold a basic level spell or ability as its anchor. But as you raised the grade of the core you could choose to either increase the level and complexity of the original anchor or increase the number of applications available.
The problem with Kaleb's body was quite simple, the energy of the world didn't flow through him. This was not to say that he did not have any vital energy that all humans produced to stay alive, but that the energy of the world that flowed through everything, living and nonliving, did not seem to be able to enter his body. When Kaleb asked why this was a problem, Rackshar explained that without the ability to use that energy he would never be able to produce magic or cores because he couldn't gather energy to create either.
Kaleb had yet to move from his vantage point on top of the dune as he pondered that news. His thoughts on the matter were interrupted as he saw movement in front of him. Down in the valley between dunes he noticed the sand shifting as if something was moving underneath it, and that trail of displaced sand seemed to be coming quickly toward him!
Rackshar noticed his distraction and when he saw what Kaleb was looking at he yelled 'Run kid!'