Arthur sat on the rocky ground and listened as Ra told him about the world of Arebos.
Within the universe there were numerous world. Each world a variation of reality spun from a different blend of cosmic forces. Many worlds can be similar where others are totally different.
Terros was similar to Arthur's world where as Arebos was a totally different world. It was an immaterial realm. There was no physical matter in this world. It was purely a world of spiritual energy and spiritual essence.
The living beings in this world were spirit beings. They were not bound by biological processes like growth and reproduction and their souls were not bound to a reincarnation cycle or mortal life force.
Where other worlds had birth, Arebos had incarnation. Evolution instead of growth. Living beings survived by absorbing spirit energy. Death happened when the spirit core was destroyed and the soul essence drifted within the world accumulating spirit energy until the next incarnation.
This world would be perfect for Arthur to replenish his soul energy as well as growing stronger.
Ra went on to explain the nature of souls in the universe.
Every cosmic interation had a Divine being to which that world's existence and casuality was anchored. Souls were simply fragments of that divine essence. The souls of lesser beings like animals and mindless spirits were diluted fragments while intelligent beings with conscious wills were purer fragments woven from the raw divine essence, the purest form of cosmic essence in any world.
Mana or spiritual energy was condensed divine essence, that is why it responded to will and could affect and shape reality. In other words, soul energy which was inherently divine essence could be condensed into mana and mana could be broken down to soul energy.
The cosmic rules of Arebos will allow Arthur to draw in spiritual energy and cultivate his soul energy.
However that was not what Ra wanted for the boy. Arthur wanted to change the Fate of his hero and there by the Fate of an entire world. For that, Arthur had to grow in power. He had to attain power beyond what the hero attained at his final battle. That way he would be in position to help the hero grow stronger and be able to protect him from any consequences of changing fate.
This world would be the start of that growth.
As Arthur was now, even if he got a material body, he would be cannon fodder in the war against demon kind. He wouldn't be able to affect anything. He would only be able to escape with his soul at the last minute.
Ra wanted Arthur to use this world to grow stronger.
When Arthur asked Ra how he would grow stronger, Ra told him he would only share that information if Arthur completed Ra's training successfully.
And so Arthur begun his training within his soul space in the void between worlds.
There wasn't much to the training. Arthur simply had to learn to condense soul energy into spirit energy and how to control that energy.
Easy right? Guess again. It was the hardest thing Arthur had ever done in his existence ever since he tried to walk with his own body. It did not help when Ra revealed that spirit energy is condensed naturally by Divine beings.
Luckily for Arthur the training was within his consciousness. The soul energy he was using was imaginary conjured from his memory. Ra told him as long as his will mastered then it would imprint upon his being. Otherwise Arthur's soul energy would have been depleted.
Ra had demonstrated for Arthur. According to Ra, one's will flows within their soul energy and thus they should be able to achieve this feat easily. especially someone who was actively conscious and aware of his soul energy.
Arthur's Astral form was already an application of manipulating his soul energy. But that was instinctual according to Arthur.
But Ra rejected that notion.
"There is nothing instinctual about your astral form." Ra had said to him.
" You must have wanted something so desperately with your will that you pushed at all corners of reality until something manifested. Tell me Arthur, what is it that you so badly wanted and were denied by the world?"
As Arthur sat his focus on the imaginary mass of swirling blue energy before him, he thought of Ra's question. And the answer came unbidden.
He desperately wanted to escape from his body. from the weakness that bound his existence. from the prison that his body was. From the darkness of his dreams.
And unconsciously He must have Awakened his astral projection. He built himself a body that would be free. That would not be shacked, not even by a world!
Arthur remembered the bubble he had woven easily to protect his thoughts from Ra.
Soul energy was the medium of one's will and the force that fuels it. Arthur was the incarnation of his will. Soul energy was bound to his will. And so he communed with that energy, bringing it together, pushing it tighter and tighter together until it condensed before him. the swirling mass of blue energy became a tiny ball of energy before Arthur. Spiritual energy. He had done it. Then it exploded in his face dissipating. Ra laughed in his face.
It would take very many more tries until he learnt that he had to will it to stay in that form.
To Arthur it felt like days passed and they turned to months and they turned to years. He was worried he would come out of this soul space when the world of Terros was long gone.
But Ra did not relent. If Arthur hoped to help the hero then he had to atleast accomplish this much.
Eventually Arthur got the hung of it. Where soul energy was like aura or rays of light, spirit energy was like actual flames that gave off the aura or the light. it was like essence existing between liquid and gas.
But that was not the end of the training. Arthur has to learn how to manipulate this spirit essence. Spirit essence was shaped by will, but it required more than just desire. it required structure, intent and understanding of the desired effect.
However it was much easier than condensing soul energy.
Arthur was able to craft a sheild made of spirit essence. he was able to ignite it and form flames, even weave them into fireball and also shape a blade and a spirit core. He felt like he had lived through three life times just training in this place.
But his determination could not be denied. Ra was impressed with the boy. his ability was frightening, not that he would tell him that. Ofcourse Arthur had advantages. He had Access to the full functionality of his will. Living beings could only access a fraction of their will through their bodies or vessels. Arthur was the manifestation of his conscious and unconscious will. This made his full will very potent.
After that training, Ra simulated an environment full of spiritual energy so that Arthur would learn how to cultivate it. Draw it in and shape it. When Arthur asked why he had to go through this Ra answered him.
"Because you will have to create your own spirit body to survive in this world!"