I barge into the room and come face to face with the source of the dark magic and it was…….me?

On the other side of the door was another me, it's like staring into a mirror. Everything was the same except the eyes, it had dark red pupils compared to the blue pupils that I have. "Well, aren't you a clever boy?" It mocked, even the voice sounded exactly like mine, before I could even react the other me flew towards me, grabbed my neck and sent me flying down into the floor of the infinite doors chamber.

*Cough cough* I coughed out the dust and prepared for a fight.

"Well I didn't expect you to actually find me that fast. But apparently you are smarter than you look." The other me slowly descending to the floor, standing in front of me. "Who are you? And why are you taking my form?" I started bombarding it with questions while holding the longsword with both my hands at the hilt.

"Me? I am Erebus, the personification of darkness." The other me answered. "As for your second question, well…. I took on the form of the host I inhabit." He said, then attacked me with his bare hand. I defended myself with the sword, but was sent flying and crashing into a wall.

His attack knocked the wind out of me, and it was so strong that I had to use the sword to support myself up to a standing position. "Well if you haven't reacted in time, you would've probably lost an arm or even died." He remarked, looking unimpressed.

Next, he summoned the same sword I was holding.

"Now then, let's have a proper fight." His smile was disgustingly wide, like he looked excited to torture me during the fight.

His attacks were quick and heavy, I could do nothing but block them and try not to get hit.

"Come on! Come on! You can't just keep on defending. What will Art or that time mage say if they saw you fight like this." It kept taunting me as it kept barraging me 

with attacks.

I saw an opening and moved to strike, but he managed to block and counter it, giving me a kick to the face which sent me flying, bouncing a few times off the floor before rolling to a stop. My sword flew off a few distance from where I was.

"Hahahahaha you're even more pathetic than I gave you credit for! Even after being trained as a mage you still move and think like a normal human." Erebus belittled. 

Beaten and humiliated on the floor, I dragged my beaten body to my sword a few distance away.

A leg kicked the sword away, as I looked up Erebus smiled creepily at me and picked me up by the neck, pinned me against the wall, choking me.

"You're weak Boy! And that's why I will take my time making you suffer. Hahahahahahaha!" He said gleefully as I struggled to get him to release me.

A sharp pain suddenly pierced my abdomen. "Arrrrrgh!" Was all I could let out

A blade through my abdomen, as Erebus continued to push it even further in.

"I'm gonna die! I'm really gonna die! There's nothing I can do." my mind freaking out as Everything around me started to go dark.

Erebus placed his palm on the back of my head and said "When I take over, I'm gonna kill that time mage, followed by the two friends you're so close with. And all you can do is die knowing that you can't save them. Hahahahaha"

He released my head, and summoned the sword on the ground to his hand. "Well it's been fun tormenting you. But I have people to kill and chaos to create. Farewell Boy!" He swung the sword towards my neck…

*Kang*

 A loud sound rang out as my hand blocked the blade on its own.

"….won't… let….. you…." I said weakly

"What was that?" Erebus asked sarcastically.

"I won't let you!" I managed as I grabbed the sword blade and pulled him closer and headbutted him.

As he retreated from the pain and surprise, I pulled out the sword from my body. And quickly got into a battle stance, imbuing my weapon with mana.

Erebus recovered and looked at me, shocked. But his facial expressions change into pure glee in 5 seconds. "Finally a challenge!" He let out a smirk.

I clutch my sword as if I'm about to swing a baseball and ran towards Erebus.

He did the same thing and as our blade met a shockwave rang out. We exchanged blows a bit, with none of us gaining the upper hand.

"Even after being trained as a mage, you still move and think like a normal human." Erebus' remark had left an impression on me.

I began to try something hoping I won't look like a fool. {Dark crescent slash} I yelled as I swung my blade. A black crescent shaped beam came from my blade and flew towards Erebus which surprised both of us. But I knew if I wanted to win I had to take advantage of his surprise and defeat him, so I rushed towards him and attacked. Not having time to react he tried to defend but I managed to disarm him, and point my sword at him.

He moved to attack me while unarmed, I countered and the next thing I knew, my sword had impaled him in the chest.

"Heh…*cough* not bad kid…. It seems I have to submit to you…. For now." He said looking like he gave up, he then warned me "don't you ever let your guard down, not even for a single second because the moment you do. I will not hesitate to kill you." And with that he vanished into ash, I fell back and lay on the ground feeling exhausted I fell asleep.