Wrathful Demon Energy continued to rush towards Leon like water from the opening of the floodgates. The sheer amount wasn't something a normal person could digest at once.
However, Leon swallowed as much as the Wrathful Demon Energy threw themselves at him.
Just like Leon himself, his Black Vortex Space was an abnormal existence. It devoured everything with a bottomless appetite and continuously churned out dark energy for him to refine.
Nevertheless, Leon had sorely underestimated his dark energy core's growth potential limit. Twofold was just the beginning.
As time flowed, the dark energy core increased threefold, then fourfold.
At that point, the dark energy core's size increased at a noticeably slower rate as the dark energy within became denser and compacted instead.
Ultimately, the dark energy core stopped growing in size after reaching fivefold.
'I am definitely at the Peak stage of Heaven Ascension Realm now…' Leon silently determined as he continued to gather dark energy for his breakthrough.
After increasing to fivefold, the dark energy core became fragile like glass. As such, Leon slightly lowered his absorption speed and proceeded with care.
But as his fivefold dark energy core regained its density, it became hard as a rock. It became increasingly difficult to compress dark energy into his dark energy core from that point onward.
No, it was more accurate to say that the difficulty skyrocketed.
'It seems like I am finally reaching the absolute limit of energy compression now… But would my dark energy core sprout like a seed once I surpass the limit? I feel like it will just crack and explode…' Leon furrowed his brows.
Fortunately, he had placed his dark energy core in a spot that wasn't directly in line with his soul core.
Thus, even if he failed and caused his dark energy core to explode, the Black Vortex Space would swallow the eruption of energy.
Due to his lack of knowledge, there were potential risks. Still, his safety was ensured. He could proceed fearlessly.
'I have already reviewed the Devil Emperor's Tome of Eternal Darkness many times. It's time to take the final step,' Leon decided with resolution.
He followed the next step in the Devil Emperor's Tome of Eternal Darkness and activated the dark power with his dark energy core.
Due to its high density, it was incredibly difficult to manipulate the dark power in the very center of his dark energy core.
Nevertheless, with the sheer might of his Divine Will, Leon overcame the challenge.
The dark power in the heart of his dark energy core twisted and turned, revolving in a very specific yet omnidirectional pattern.
As a result, a sphere of revolving dark power was formed within the core of the dark energy core.
He was trying to create the embryo that would give his life to his dark energy core and allow it to sprout like a newborn plant, according to the Devil Emperor's Tome of Eternal Darkness.
Nevertheless, Leon was missing one crucial component to finalizing his goal. Fortunately for him, he had just what the embryo needed.
All primordial cultivation methods required True Grandmist Energy to achieve the maximum benefits of the primordial cultivation methods. The Devil Emperor's Tome of Eternal Darkness was no exception to that.
Leon started channeling dozens of True Grandmist Energy threads into the dark energy core and forced them to worm their way to the embryo.
The True Grandmist Energy threads were quickly caught in the rapidly revolving embryo before being pulled straight into its center like a vacuum.
When that happened, it was like a miracle drop of water on a dry plant during a drought, causing a miraculous change to take place as the embryo came to life.
That being said, Leon could not help but think the process was similar to how humans create life—if he was to ignore the fact that the embryo didn't actually come to life.
It was just a metaphorical term for the change taking place within the embryo.
As Leon continued to feed threads of True Grandmist Energy to the embryo, it transformed into a swirling tempest.
In that instant, it started pulling in the surrounding dark energy within the dark energy core, like bits of dirt and debris being ripped off the rock walls.
Afterward, the swirling tempest of energy quickly grew and drilled its way out of the dark energy core like a hatching egg.
Ka-cha!
The top of the dark energy core cracked open as the swirling tempest rushed out like a powerful eruption.
But as it did, it lost its form and scattered like countless black lightning strikes branching out from the dark energy core's opening while solidifying rapidly at the same time.
Gradually, the momentum died down until it completely stopped, and what became of Leon's dark energy core was a 1500-feet black tree of darkness.
It didn't have any leaves and didn't look alive, but it could definitely be felt. The tree of darkness overflowed with power as clouds of dark energy poured out from its branches.
However, the dark energy was not the same as moments ago.
It was thick like lead yet formless like the clouds and contained a certain depth and richness of power that completely eclipsed its former self.
The dark energy had undergone a huge qualitative transformation.
'Is this what it feels like to step into the Truth Manifestation Realm with a fivefold dark energy core?' Leon felt an endless source of power coming from his tree of darkness.
'The average cultivator was said to possess a 300-feet tree of energy called the Truth Manifestation Tree upon reaching the Truth Manifestation Realm, but mine grew to 1500-feet…'
It was definitely not something that would have fitted inside the confinement of his upper energy center – or so Leon thought.
However, the space around his 1500-feet Truth Manifestation Tree of Darkness was warped like a special barrier.
Within the spatial barrier was an expansive space for the 1500-feet Truth Manifestation Tree of Darkness to grow endlessly and only occupied very little space outside of the special barrier in the Black Vortex Space.
'Seems like my worries were for nothing,' Leon smiled wryly.
Nevertheless, moving the dark energy core to his Black Vortex Space was something he had to do regardless of whether the tree could fit in his upper energy center or not.