After considering the strong arguments for both stability (Earth) and speed (Fire), and remembering the ambiguous "Plant or Wood Element" of his sword, which likely required both Earth and Water, Kaelus settled on the S+ Fire Element Core of the Two-Headed Crystal Wyvern. Fire would give him access to Lightning and Plasma, elements he knew would significantly amplify his combat mobility and damage.
He positioned himself cross-legged in the middle of the training area. Sylva, having been handed a special grimoire by Aethon the night before for just this occasion, lent it to Kaelus.
Kaelus opened the grimoire and refined it. After that, the details appeared and it wasn't a spell book but a complex diagram detailing the safest, most efficient method for a mage to integrate a monster core into their own system. The first step was preparation: focusing his entire mana pool to create a stable, receptive channel within his body, primarily targeting his existing Wind Element locus. This process took nearly twenty minutes, transforming his internal energy system into a glowing, rotating vortex.
Finally, he placed the brilliant, crimson-hued S+ Fire Core on his sternum and began the absorption process.
A blinding, intense red heat immediately erupted from the core, searing against his skin. This wasn't merely heat; it was pure, concentrated elemental essence, alive and aggressive. Kaelus gritted his teeth, forcing his mind to remain utterly still as the energy began to dissolve into his body.
The energy, thick as molten glass, flowed into him. It met his Wind Element core, which was accustomed to flowing, gentle power. The clash was violent. Crimson fire lashed out, meeting roaring emerald wind. Outside, the air around Kaelus began to shimmer, turning a deep, dangerous orange and red. The ground beneath him began to crackle and smoke as residual Fire Mana escaped his control.
The essence hammered against the walls of his Dragon Core, attempting to carve out its own space. The pain was immense, feeling less like integration and more like a hostile invasion. Mana flowed out of his Dragon Core in a desperate torrent to counter the Fire energy. He could feel his Wind mana, the foundational energy of his current self, wrapping around the invading Fire, attempting to subdue it. Every internal energy channel felt like it was being scraped raw, then immediately cauterized by the foreign heat. He pushed harder, relying on the sheer tenacity of his Dragon Core to survive the process.
The dragon's natural resilience proved superior. His Dragon Core began to draw the foreign Fire essence inward, not to house it, but to consume it. The intense crimson energy was filtered, stripped of its elemental properties, and converted into raw, pristine mana. The fire raged one final time before being completely devoured.
The S+ Fire Core instantly withered into dust, fully consumed. Kaelus opened his eyes, feeling the surge of raw energy. He inspected his Dragon Core, and a wave of confusion hit him. The Fire Element was gone. His Wind Element core had completely converted the new power into pure mana, strengthening his Dragon Core and dramatically expanding his overall mana pool. He hadn't gained an element; he had gained raw power.
Then, his body began to violently pulsate. This was the sign of a breakthrough.
Kaelus, originally at the Peak Stage of the 7-Star Dragon Rank when he left the cave, had broken through to the Initial Stage of the 8-Star Dragon Rank after the monster wave. Now, the sudden absorption of S+ core energy had put him on the verge of another breakthrough. Visible, intangible mana began to swirl around his body, gathering like a thick, turbulent mist.
The other members watched from the wooden bench with straw roof, their eyes wide.
"I cannot feel the Fire Element in him, but what we're seeing right now is a sign of a breakthrough," Sylva whispered, confused by the strange process.
"So it means he will be successful in jumping from 4-Star Mage to 6-Star Mage!" Zane said, referencing the human mage system where a 6-Star Mage possesses two basic elements.
"But there should be Fire Mana radiating in his body, not just raw mana," Vara noted, still feeling the invigorating effects of her own breakthrough.
"Come on, it's Kaelus," Zathis grinned, itching for a spar. "He cannot be explained by common sense. The fact that he's on the verge of a breakthrough means he will succeed."
A massive mana fluctuation alerted the Guild Master. Aethon, exhausted from running from the main hall, burst onto the scene. "Where's Kaelus? Is he successful?"
"Look!" Kaelan shouted, pointing at Kaelus, who was enveloped in the surging mana.
Aethon threw his head back, a wide smile splitting his face. "FINALLY! This is the future Hero coming from the Dragon's Fury Guild!"
"Guild Master, you are too excited," Zane chuckled. The others burst into laughter, breaking the tension.
Meanwhile, Kaelus felt the surge of power intended to push him to the Mid-Stage of the 8-Star Dragon Level. He knew there were too many spectators for him to contain the sudden eruption, but the power wasn't enough; the surge began to slow, threatening to cut short his breakthrough. Failing now would destabilize his Dragon Core.
He needed more energy, immediately.
Kaelus made a snap decision and mentally summoned the other S+ core: the Earth Element Core of the Armored Scorpion. He pulled it from his Dragon's Void and, without hesitation, consumed it like the Fire Core.
The others watched in shock as Kaelus suddenly materialized a second S+ core and began integrating it.
"Kaelus!" Sylva screamed, jumping up. "What are you doing!? If you do that, you might die!"
"Stop, Sylva," Zane ordered, holding her back. "I think he has a reason. Let's just watch."
Aethon watched, his eyes worried but also wildly excited. "He's so reckless, but I like it. I'm really excited about this."
"Whatever the result will be, if he dies, then so be it," Zane said, his expression grim but resolute. "But if he succeeds, it will be a huge boost to our combat power. I am worried for our next mission, but if he succeeds, the mission will succeed also."
Sylva was furious. "Then I guess we have to wait then! In the entire mage system, a Peak 4-Star Mage is ineligible to consume any core. He needs to be a 5-Star Mage just to attempt one! But a 4-Star Mage attempting to refine two cores of different elements at once—that's insane! He's trying to jump from 4-Star to 8-Star just by having three basic elements! He doesn't even have an enhanced element or a deviant element! He is insane, purely insane. I hope he'll succeed so I can hit him in the head!"
Kaelus ignored the commotion. As he consumed the second core, the nearly stopping power surge boosted again, roaring back to life. His body began to swell as the surrounding mana, coupled with the Earth Element core, was ruthlessly devoured by his Dragon Core. The process was agonizingly painful but felt, strangely, like the necessary conclusion. He inspected his core one last time, confirming the Earth Element Core provided just enough essence to push him through.
Then, the sky above the training area suddenly dimmed.
A powerful, visible wave of mana, the Heavenly Manifestation of Mana, poured down from the sky and enveloped Kaelus. He had successfully broken through to the 8-Star Mid-Rank Dragon Level. The swelling instantly receded, the volatile surrounding mana was sucked into his core, and his energy system solidified into a state of immense stability.
Kaelus opened his eyes, a small smile curving his lips.