Kretos didn't wait for the Demon Empress to respond and immediately charged with his sword at hand. His body was still aching from the last battle, but he couldn't care less. He had stormed the strongest demon's castle because he wanted to fight.
The moment he was within one meter of the Demon Empress an invisible force stopped him from moving forward, but that just made Kretos all the more excited. On the other hand, the Demon Empress was shocked to see that Kretos wasn't disintegrated by her mana barrier instead he was just immobilized. She looked curiously at the viciously smiling Kretos.
"You are the demon from the Shadow clan that has been going on a rampage lately... Aren't Shadow Clan members good in the art of assassination, why are you attacking this way?"
"Assassination?... What's the fun in doing that?!" Kretos shouted as he broke through the barrier. The Demon Empress was slightly surprised as she raised her finger to block Kretos's attack. Yet the moment her fingernail came into contact with Kretos's sword, she immediately knew that it wasn't enough. She then used her full hand to block and was greatly surprised by Kretos's strength.
'Unfortunately this isn't enough.' The Demon Empress raised her free arm and shot a ball of pure mana at Kretos. Seeing the incoming attack Kretos couldn't dodge but he smiled a very crazed smile as it hit. The Demon Empress was surprised to see that expression on her opponent's face. Usually when she attacks the only expression her opponents have was fear. Yet Kretos showed a very crazed joy as he was about to get hit.
The ball of mana blew away Kretos who crashed from one wall of the castle to another. When he finally stopped the Demon Empress was sure that should've killed him. But instead, his mana fluctuation was spiking to a level that equaled hers. As she noticed this, she remembered when she sensed him fighting the goat demon, didn't he also had the same level of mana as her subordinate, but now it equaled hers...
'Did he hold back to gauge my mana, so we can fight on an equal footing?... Does this mean he has more mana than me?'
The Demon Empress was finally realizing that the young demon in front of her wasn't as easy to handle as she thought he was.
"Now that's what I'm talking about! Now I can finally go all out!" Hearing Kretos's joyful voice the Demon Empress finally stood up from her throne. The moment she did so, Kretos suddenly appeared before her as if he teleported.
The Demon Empress evaded the incoming strike and shot another ball of mana at Kretos who was now able to evade. The Demon Empress then tried to get some distance so she could unleash a stronger attack, but Kretos wouldn't let her.
Kretos continued to stick close to her unleashing a barrage of sword slashes happily. He evaded he attacked, it was so much fun for him. No matter how fast he went the Demon Empress was able to evade and counter.
This was the first time he went into top gear and he still couldn't hit the Demon Empress. This made him ecstatic. On the other hand, the Demon Empress noticed that for each attack Kretos made he was slowly getting faster, his attacks getting sharper.
'Is he still holding back, or is he growing during this battle?...' If it was the former then it was still alright, but if it was the latter then the young demon was more frightening than she thought. She needed to end this quickly before his improvement surpasses her.
The Demon Empress suddenly fought more aggressively no longer minding getting nicked by Kretos's sword for as long as she could hit him squarely. Seeing her change tactics, despite him being the one getting pummeled, Kretos was happy. This was the kind of opponent he wanted to face. It wasn't a mistake to have raided this castle.
"You're the best, truly spectacular! Show me more, bring out more of your power!" Kretos slightly provoked the Demon Empress. Yet despite the provocation the Demon Empress didn't bother as she continued trying to hit key parts of Kretos's body.
...
After fighting for a few minutes Kretos felt that something weird was going on. The Demon Empress was full of wounds but despite that she still fought aggressively. Though that was what Kretos wanted, he felt like the Demon Empress wouldn't be doing that without a reason. Kretos then felt his body going numb as he couldn't move.
The Demon Empress sighed as she saw the sight, her attack finally came to fruition. She was from the Succubus clan and her specialty was illusions and soul control. She had been slowly trying to control Kretos by injecting a portion of her soul into his. As the current strongest Succubus, usually even a small portion of her soul would've made even the hardiest of demons collapse under her control. Yet it took her great amounts of her soul to even stop Kretos.
As she was feeling relieved she felt the soul fragments that she injected were being destroyed. It was at that moment she felt an overwhelming force within Kretos's soul. It was so profoundly powerful, that it made her feel extremely insignificant. As she was distracted Kretos was able to easily stab her in the chest.
Unlike other demons her vitality was weaker, that was one of the weaknesses of the Succubus clan that excelled in spell casting. Her life force was slowly draining, and she could no longer heal as a part of her soul was crushed by the unknown force.
"NO!!! What the f*ck! Why didn't you evade?! Damn it, we were having so much fun!" The Demon Empress heard Kretos's cry as she lay on the floor. Hearing the young demon's desperate cry for more battle, made the Demon Empress giggle.
"I'm sorry young demon, that I have disappointed you..." Kretos looked at the dying Demon Empress with a weird expression on his face.
"You didn't disappoint me... It was actually the most enjoyable battle I had so far." The Demon Empress smiled as she heard what Kretos said.
"Is that so... Young Demon, since I was able to satisfy you, can you fulfill a wish of mine?"
"... I don't know if I can fulfill your wish, but I'm willing to listen."
"Don't worry, it's alright if you can't do it... You see I once had a dream of uniting the whole demonic tribes and clans. Unfortunately, I wasn't strong enough to do so. Seeing your strength today, made me think of that dream once more. If you can, I wish you could unite the demon race into a powerful Kingdom."
"Will I be facing strong opponents?"
"Yes, many will come to face you until you feel despair." Hearing what the Demon Empress said made Kretos laugh.
"The more the merrier! Now that would be a battle worth fighting!" Seeing the young demon laughing so heartily made the Demon Empress believe that there might actually be a chance for him to fulfill her dream. Unfortunately she wouldn't be there to witness the fruition of her dream.
"If only I met you sooner..." The Demon Empress drew her last breath, but before she died she heard Kretos say something.
"Thank you for the battle, and for the dream..."