The Furnaceback Centipede had possessed two elemental affinities.
Earth and fire.
However, Simon’s fire affinity had not increased even after Devour ended.
The reason was simple.
His current proficiency with Devour was not high enough to extract and refine both affinities from a Half-Step Abyssal Beast at the same time. The moment the skill reached the deeper parts of the centipede’s essence, Simon felt both elements and understood that he had to choose one.
Improving his weak fire affinity had been tempting.
However, he already possessed fire and he could increase it in the future when he evolved his bloodline.
Earth was completely new, and more importantly, it could strengthen his body, increase his defence, and make the physical essence he absorbed easier to endure.
So Simon chose earth.
’When my proficiency improves, I might not have to make that choice again.’
For now, High B grade earth affinity was more than enough.
Simon sat down again inside the lava cave and placed one hand over his chest.
He could feel the heavy beat of his Infernal Heart beneath his palm.
Becoming a Prime Archfiend was different from every advancement he had undergone as a Lesser Demon and a Fiend.
Back then, cultivation had focused mostly on the Chaos Flame.
A demon absorbed demonic energy, refined it, and used it to make the flame larger, denser, and more stable. The stronger the flame became, the closer the demon moved toward the next stage.
That method ended after becoming an Archfiend.
An Infernal Heart did not advance by simply feeding more energy into its Chaos Flame.
It advanced by refining the heart itself with his Chaos.
Simon remembered his breakthrough clearly.
He had entered the space within his Chaos Flame and faced the five affinities he possessed at the time- wind, space, shadow, fire, and ice.
Each one had been separate.
Each one had carried its own nature, pressure, and resistance.
Simon subdued them with his Will and fused them into the Chaos Flame one after another. Wind had been the strongest. Space had been dangerous, but his experience from his previous life allowed him to control it. Shadow, fire, and ice had followed.
But combining the affinities had only been the first half of the breakthrough.
Afterward, Simon compressed the entire Chaos Flame.
Smaller.
Denser.
Again and again until all of it existed within a single point.
Then he allowed it to implode.
The detonation had not spread outward. It had erupted inward through his Demon Heart, engraving elemental Chaos into every layer of it.
Flesh.
Blood vessels.
Pathways.
Every part of the heart had been touched by his Chaos.
That was how his Burning Heart became an Infernal Heart.
If his control had failed, the Chaos Flame would have exploded incorrectly, shattered his heart, and killed him.
The lesson from that breakthrough had been simple.
Chaos was not merely power.
Chaos had to be controlled.
Now, the same lesson continued into his cultivation as an Archfiend.
When an Infernal Heart was first formed, Chaos existed throughout it, but the engraving was still shallow. It was like a mark scratched across metal. The mark was present, yet it had not become part of the metal itself.
Refinement deepened that mark.
An Archfiend first absorbed demonic energy into the body. The energy was then sent into the Chaos Flame, where the unusable parts and impurities were burned away.
What remained was no longer ordinary demonic energy.
It became the demon’s personal Chaos.
That refined Chaos was then driven into the existing engravings inside the Infernal Heart. Each cycle pushed it deeper into the heart’s flesh, pathways, vessels, and inner structure.
The heart became denser, stronger, and more resistant.
It also became more capable of containing and producing more Chaos than before.
That was Infernal Heart refinement.
The percentage did not measure the size of the Chaos Flame.
It measured how much of the Infernal Heart had been properly saturated and tempered by its own Chaos.
From zero to twenty-five percent (0-25%), a demon remained a Minor Archfiend.
At twenty-six percent (26%), the first threshold was crossed and the demon became a Prime Archfiend.
From twenty-six to fifty percent (26-50%) was the Prime stage.
At fifty-one percent (51%), the demon became a Superior Archfiend.
Seventy-six percent (76%) marked the beginning of the Supreme stage.
And at one hundred percent, the Infernal Heart had reached the absolute limit of its current form.
Whatever came after that would involve transforming it into a Forged Heart, but Simon did not need to concern himself with that yet.
’Becoming a Prime and beyond in the Archfiend realm is my main concern now.’
The first advancement was the simplest of the three Archfiend refinements, but simple did not mean easy.
The Chaos engravings inside a Minor Infernal Heart were new. To reach Prime, an Archfiend repeatedly forced refined Chaos into those engravings until they penetrated more than a quarter of the heart.
The process also burned away impurities left within the heart and body.
As the demon approached twenty-six percent, the heartbeat became heavier, the Chaos Flame grew restless, and the heart resisted the power being driven into it.
Once the threshold was crossed, the Infernal Heart would contract violently and pull the surrounding Chaos inward.
Then the Chaos Flame would erupt with greater strength.
That was the Prime stage.
Prime to Superior followed the same basic process, but the easy portions of the heart had already been refined. The Archfiend had to push Chaos into deeper and more resistant layers.
At that point, control became even more important.
Superior to Supreme was worse.
The final portions of the heart resisted refinement the most. By then, every heartbeat carried increasingly pure Chaos through the demon’s body, and the Infernal Heart slowly stopped behaving like an ordinary organ that contained Chaos.
It became an organ built for Chaos.
For an ordinary Archfiend with one affinity, the process was direct.
Absorb demonic energy.
Refine it into elemental Chaos.
And temper the heart.
Simon no longer had five affinities.
He had six.
Wind, space, shadow, fire, ice, and earth all had to pass through the Chaos Flame and enter the Infernal Heart without destroying the balance he had temporarily created.
He could not simply suppress the weaker affinities and allow wind to dominate everything. The deeper the refinement went, the deeper every imbalance would also be engraved.
’If I refine the heart incorrectly now, I will be strengthening the flaw along with the heart.’
That was the true danger.
His enormous energy reserves, Devour, the Miser’s Ring, his Will, and his control could make him advance quickly.
But none of those advantages allowed him to refine carelessly.
Simon straightened his back.
The raw demonic energy taken from the Furnaceback Centipede gathered around his Infernal Heart, waiting to be used.
He closed his eyes and the Chaos Flame rose inside his chest.
Then Simon began his first refinement cycle toward becoming a Prime Archfiend.