I created my own system

At first, Apollo froze at the revelation, Nero's words echoing in his mind. His thoughts raced, connecting dots that had always eluded him. He recalled the strange, inexplicable moments when he felt his actions or thoughts were subtly influenced, especially when dealing with matters involving the imperial family. The best example was the replica of Excalibur found in one of the temples of the Monastery. He went crazy and almost lost control of himself at that time.Nôv(el)B\\jnn

"An oath…" Apollo muttered to himself. His hands clenched into fists. "That's why."

He finally understood. As a member of one of the four ducal families, he was bound by this ancient oath, a pact that transcended generations. It wasn't loyalty—it was a compulsion, a force embedded in his very existence. An oath that goes stronger as time passes; as long as the bloodline of the four houses and the imperial family continues, so does the pledge of loyalty. A vow that can go on for an eternity.

"So that is why it was called the eternal oath, it's something that can last forever as long as the bloodline continues. Now I wonder what are the conditions of this pact. I am sure my ancestor is not stupid enough to form an oath that put absolute power into the imperial family, there has to be something that I can use"

He was always rebellious when someone tried to control him, so his first thought was about the limits and boundaries of the oath. Can he take advantage of it, or what condition he needs to do for the oath to allow him to kill Nero? When he first approaches and his bloodlust leaks, it must be perceived as an act of threat to the life of one member of the imperial house. So now what if he doesn't have any intention of harming Nero's life, only capturing him? Or perhaps he should erase his intention of harming the former king and only thing of disciplining him, in the form of violence of course. Can he fool the oath, or can Nero just control it? He wanted to test those thoughts, so he would come up with a spell to only restrict his target.

"Somehow this reminds me how my brother's teacher found that little loophole in his oath and place a fucking seal on me, he can't kill me so he just seals me away so that people can just abuse me"

After those thoughts, Apollo then moved swiftly, summoning the power-up versions of the techniques he got from Mahika, chains made from the fiery power of the planet Venus manifested and restrained Nero. The chains glowed with a red light, reinforced with layers of star energy. Nero's smug expression faltered as the chains coiled around him, constricting his movements.

"Just be a good boy, dear king," Apollo said coldly. "Surrender now," he added strengthening the restraint even more.

But Excalibur flared with power, a golden light surge clashing with the chains. Apollo frowned as the sword nullified his binding spell. Though Excalibur couldn't directly harm Apollo at the moment, it created a stalemate—Apollo couldn't harm Nero either.

Nero smirked again. "See? You can't completely harm me, the power of the sword nullifies any attacks that may harm me. So you can't kill me, demon. So just turn your back before the four ducal families arrive"

Apollo didn't pay heed to his words and just focused on how to knock the chatterbox unconscious. He needed to incapacitate Nero without alarming Excalibur's protective shield.

"How about the authorities"

[The sword senses it, it will react and might disconnect Nero from the influence of the authority]

The boy felt that frustration was slowly creeping its way towards his mind.

"And the most stupid fact that I just realized right now is this idiot doesn't know how to fully unleash the power of the sword because he is not its true master. All this time, I am struggling against a base Excalibur!"

[What do you think would happen if the sword recognized Nero as his true master?]

"Then I would immediately turn the time back to when he was just born and kill him off without thinking about the time paradox that may come later"

Then he tries to cast Void Lock, a spell designed to nullify the flow of energy in an area, hoping to dampen Excalibur's influence just like before. But the sword's runes resisted, forcing him to layer multiple spells just to hold the stalemate.

Meanwhile, the oath's power began to manifest it seems Nero triggered it or perhaps even manipulated it. Apollo felt a massive headache followed by an invisible force gripping his body, stirring it in a way that his emotions were getting haywire. He is being guided to release his hold over the troublesome king and aid his escape.

"I am lucky that this idiot doesn't know that I am from the four houses or else he might concentrate the power of the oath on me"

[I am certain of that, Creator. May I recommend that you fully transform into a demon? In our understanding, the oath comes from the blood that dwells in you. So if you transform into a complete demon form your blood will entirely be different]

"Are you certain Jeremiah?"

[I just modified the skill Demonification and demonized the original skill. This modified version changes your body including the structure of your DNA. Once you activate the skill you will become an entirely different individual, or more to say demon]

It was a good plan; however, if Apollo uses that skill, he is obligated to use only his demonic skills while his nondemonic ones will be restricted, just like before. He can only use one non-demonic skill at the same time.

"Well I think that is better than being manipulated" he defeatedly said as he brought forth his command "Activated the skill"

[Affirmative Creator]

Apollo's body was surrounded with light, a black ominous light. As the skill activated, a black knight emerged, wearing full armor and a two-horn helmet.

"Hoo.." he breathed, feeling the power of the improved version of the skill; the other Apollo also assumed the same form, rendering the oath useless.

[Notification alert!

Creator the thing you have been brewing is finished

Do you wish to take it out now]

"Yes I would like to"

The system momentarily caused the surroundings to fluctuate. Even Nero felt the sudden change. Excalibur also hums loudly as if welcoming the new challenge.

"What is this, this level of power.....Why does it feel familiar?" He questions while the sword in his hand clad him with a powerful light of protection.

The humming sound continues to be heard as Apollo's inventory releases a weapon in comparison to the sacred weapons. The weapon manifested, and as soon as it landed on Apollo's hand, Excalibur welcomed it with an attack.

A surge of energy crashes into the Apollos like a tsunami, wiping everything it reaches. A golden light filled the area to the brim, making Nero nervous that the feedback of the damage would be folded many times over like before. However, much to his surprise, something sinister intercepts Excalibur's welcome gift. A weapon born from the color of the sun and brimming with the energy of all the nearby celestial bodies in the sky came forth and blessed the ground with its calming energy. It was the opposite of the power Excalibur excluded, an oppressive and overwhelming energy.

A blade similar to the appearance of burning magma at the mouth of a volcano, symbols were also embedded at the fiery blade, while the hilt blends with the color black and orange. Then, at the center of the guard, a gem created from the power of all the heavenly bodies rested. The weapon crafted from the knowledge inside the Sage's circle was finally completed.

"Now let's do some testing," Apollo said as he closed the distance between him and Nero. The man reacted fast, seeing the incoming attack. Two different arcs drawn from swords light up the broken canyons while the ground and air bear the impact of each swing.

In the middle of all the chaos, two figures continue to clash, trying to break through each other's defenses.

"This is getting exciting!" Apollo said to himself as he felt free from all the restraints that chained him at the very start of the fight. With all his might he began executing the sword techniques he got from Mahika. The ground was momentarily under the influence of the stars as the sword's power-assisted the move Apollo was about to make. Flames began to ignite around the sword as it bore the same effects of a fire spell.

"Fire elemental sword art, Fiery blade dance"

The technique was done with a fast and continuous wave of the sword, making it hard to defend from. However, Nero was able to keep up with the dance even when the strike came from an unconventional angle. Apollo just observed how his opponent was able to block him, so he changed his attack.

"Hooo..." He regulated his breathing then he swiftly shifted his technique "Lightning elemental sword art, Swift light"

The temperature suddenly increased by many folds, and Nero faced an even more powerful strike that happened faster than the speed of sound.