Reincarnated With The Strongest System

William dried his hair after stepping out of the bathroom. This had always been his routine whenever he was about to train with Celine inside his Sea of Consciousness.

He glanced at Chiffon who was sleeping peacefully on top of his bed. They had eaten dinner three hours ago, and the little girl decided to sleep early because she was still exhausted from their journey.

William, on the other hand, had an appointment with Celine, so he left the room after putting on a clean set of clothes.

He left the Villa and went straight to Celine's Residence that he had built for her long ago. This residence included a laboratory where his Master would conduct her experiments from time to time.

William thought of all of these things as if they happened just yesterday. Now, Celine was going to a far away place, and the Half-Elf didn't know when he was going to see her again. Although his Master was being casual about it, he couldn't help but feel anxious at the thought that the two of them wouldn't be able to see each other again.

He sighed as he knocked on Celine's door, announcing his arrival.

"Master, I'm here."

"Come in."

William entered the room and headed straight to the bedroom. There he saw a silver door where Celine waited for him.

The door was the entrance of the special artifact, Eternity. This was where William had trained with Celine during his childhood.

A day inside the artifact was only an hour in the real world. In order to maximize their training time, Celine would use this artifact, so the two of them could train for days, and even weeks on end, during their free time.

He had done this countless times in the past, even so, seeing Celine in her nightwear still made his heart beat a little faster than normal.

William paused to admire the beautiful elf in front of him. It was as if he was imprinting this image in his head, just in case he forgot about her after years of not seeing each other.

"What's wrong?" Celine asked as she looked at the dazed Half-Elf that was looking at her. "Come. Time waits for no one."

"Yes, Master," William replied as he laid on the bed.

He faced Celine that he had done many times in the past, and waited for the latter to press her forehead over his.

"William, this time, don't hold back," Celine said as she moved closer. "Let's have a proper death match."

"Understood, Master."

"Synchronize."

-----

Sounds of explosion reverberated inside William's Sea of Consciousness. Their battle had been going on for an hour, and none had managed to deal a decisive blow at each other.

Celine had lowered her Rank to match William's, so they were almost on even ground. The beautiful elf's battle experience was higher, but William's countless skills made up for that gap.

"Icycle Realm!"

"Darkness Domain!"

The two powers clashed and cancelled each other out. William shot several Ice Spears, Fireballs, and Wind Blades, in Celine's direction, but the latter was too fast to be hit by his attacks.

"Void arrow!" William pointed his finger and a black arrow shot out from it.

Celine sneered and fired her own Void Arrow. When the two arrows met, Celine's Void arrow destroyed William's and continued its trajectory towards the boy.

William evaded and this time, he used his dark whip to lash out at Celine. As if waiting for that move, Celine also summoned a Dark Whip and attacked William.

When the two whips clashed against each other, William's Dark Whip dispersed and Celine's Dark Whip snaked towards him like a living being.

William raised his hand and several pillars of ice blocked the whips' advance. However, they were all destroyed by the power behind Celine's attack, forcing William to back away and escape its attack range.

"Even when two similar powers are used, that doesn't mean that they will just cancel each other out," Celine explained as she fired several dark beams in William's direction. "What you are using is simply Dark Magic, while mine is True Dark Magic. This is the difference between our powers."

Wiliam summoned Stormcaller and fired a barrage of lightning to counter Celine's magical attacks. Rumbling sounds were heard when the two attacks collided, but the Half-Elf and his Master paid it no mind.

The two fought each other in close combat as Stormcaller and Celine's Deathscythe struck each other, sending sparks flying in all directions.

"Master, how can I get True Dark Magic?" William inquired when Celine distanced himself from him.

Even though he asked a question, his magical bombardment didn't stop.

After deflecting William's attacks, Celine smiled as he channeled her Battle Aura on her weapon.

"You can wield True Dark Magic once you surrender yourself to Darkness," Celine replied as she stomped her foot on the ground to propel herself forward. "You don't need to use this power because you are capable of wielding the power of all the elements.

"If you ever meet someone who uses True Dark Magic in the future, never use Dark Magic against them."

Celine didn't give William any chance to reply as her Scythe Extended like a whip that was out to cut William in Half.

The Boy wasn't fazed as he pointed his weapon in Celine's direction.

"Quick Shot War Arts," William roared. "Grand Bazooka!"

A powerful Lightning Blast erupted from the tip of the spear, clashing against Celine's powerful attack. The collision between the two only lasted for a brief moment before William's attack overwhelmed his Master's killer move.

Celine dodged to the side by rolling on the ground. Before she could stand up and continue to fight, the tip of Stormcaller pressed against her neck.

"I won, Master," William declared.

He could have cut Celine's neck off her head, but he couldn't bear to do that. She was still his Master, and William respected her. That's why, he only settled to end their battle in a way that would not leave a bad aftertaste in his mouth.

"Well done," Celine replied after half a minute. "You have really grown leaps and bounds since the last time we fought against each other."

William removed Stormcaller's tip from his Master's neck and extended a hand to help her up.

"With this, I can go to the Demon Continent without worrying about you," Celine said as he patted William's shoulder. "I'm sure that you will do well even without me."

William was her very first Disciple, and probably her last. She was very proud of him, especially during the war in the Southern Continent. The Half-Elf had also taught her a lot of lessons in life.

Because of William, Celine had changed her mindset and decided to face the things that she had been running away from all her life. This was why she wanted to see him first, before meeting her twin sister, Celeste.

After she reunited with her sister, she would then travel to the Demonic Continent to visit her Master. Celine was quite worried about her, and missed her terribly.

William lowered his head, because he didn't want to let his Master see his sad expression.

"Stop acting like a spoiled child," Celine said as she used the tip of her finger to raise William's head. "Since you have beaten me fair and square, allow me to give you a reward."

Celine moved her head closer.

William's eyes widened when Celine's soft lips pressed over his own.

"Happy Birthday, William," Celine said with a smile. "Congratulations, today marks the day of your coming of age. You are now considered an adult, so it's time for you to become one."

Yes. When the clock struck twelve, William officially turned eighteen years old in the World of Hestia. The Half-Elf hadn't forgotten about his birthday, and even made plans to have a celebration in the Thousand Beast Domain after Ashe's and Princess Sidonie's classes ended in the afternoon.

Before William could even react to Celine's words, the beautiful elf snapped her fingers. The surroundings changed, and they returned to the bedroom where the two of them laid facing each other.

"This will be our last lesson together," Celine whispered in William's ears. She once again kissed William's lips before untying the string that bound her nightwear. "Although I feel sorry about your lovers, I will be taking your first."

William looked at the beautiful Elf that was looking down on him. He would be lying if he said that this possibility never crossed his mind when he was still young. Now that Celine was actively stripping him of his clothes, he knew that his Master was serious.

"Master, I think you're making a misunderstanding," William said as he cupped Celine's face. "It's not you, but me. I will be taking your first."

William pulled the beautiful Elf towards him and kissed her passionately. This was the start of their first night together.

Not as Master and Disciple.

But as a man, and a woman who would be taking that next step in their relationship.