Problem

"My father is a Tier-5 Warrior. He go to clear a dungeon with his party. At first they easily cleared the lowest floor without any problem. But when they entered the boss room, they felt as if the world turned upside down. Although they are all Tier-5 Warriors, they felt helpless when they saw a huge red demon with two heads and four arms. They fought it for 2 days before they managed to kill it. After they killed it, they tried to find it there is mana core inside it, but what they found is a mana core that is about the size of marble in the chest of the demon. They took it and they decided to give it to my father since he is the strongest in the party. After that my father came back home. I welcomed him with my mother and he left his things in a table. Everytime my dad will come back I always check his things. That's it when I found the marble sized mana core I ate it because I mistook it as a food." Marco summarize the story that happened 10 years ago.

Although this is not a laughing matter, Zero laughed in his story. Just who the fuck will mistook a mana core into some food? Maria also can't help but laugh hearing Marco's story.

"H-hey don't laugh at my story!" Marco said embarrassingly.

Zero calmed down and asked with a serious face

"But how can you control the demon?"

"After I ate the mana core there is nothing strange happen. I also tell my father that I ate a weird looking marble. He immediately find some knowledgeable figures about demons and demon possession. They said they can't also figure it out on why and how the demon is not taking control of my body. This is the first time the demon possessed me."

Zero asked curiously

"When you ate the mana core, did you just swallow it and you did not chew it?"

"Yeah I only swallowed it." Marco answered.

"That's it! The demon is not reacting because it's still inside the core despite being inside your body. And earlier you receive an attack from the stomach which destroyed the core and let the demon loose out." Zero find a logical answer. When absorbing mana core, it must be destroyed to absorb the power inside it. Mana cores can also store souls if the carrier wills it.

Marco is astonished after hearing Zero's swords. He also find his words reasonable. But the astonishment in his face was changed by fear after realizing something and asked

"T-that means the demon can now take control of my body?"

"Yep." Zero gave Marco a thumbs up.

"But you can control it if you are strong enough making it your own power." Zero said with a serious gaze.

Although Zero is aware on how strong Marco is he still asked

"What tier are you now?"

"T-tier 2 Warrior." Marco answered while scratching his head.

"You need to be a tier-4 warrior as fast as possible or else you know the consequences. You're luck that the demon is weakened after it died and you only need to be tier-4 to control it. But if it is in its peak state, you need at least to be tier-6 to control it. If I'm always beside you, there is no need to rush to tier-4 but you know I'm not always free." Zero stated.

"H-how can I get stronger in such a short time? A week from now, me and Maria will enter the Warrior Academy in the empire."

Marco panicked.

"Actually it's not impossible to be Tier-4 within a week. But it will cost quite a sum.. Why don't you ask help to your father? Since he is Tier-5 warrior I'm sure he can buy you what you need." Zero gave a suggestion.

Maria is just silent in the side because she still cannot process all the information that entered in her head.

"Our house is in the capital because my father is now a part of the imperial troops and a general one. You must be wondering why I'm here. I'm here to fetch Maria because she lives here. It will take atleast 3 days to reach capital if we leave now." Marco spoke and Maria nodded to his words.

"Did you just say Warrior Academy earlier? What's that?"

Zero asked.

"When you reached 15 years old, you will be eligible to enter the academy. But the cost is quite high so only people who can afford is only be able to enter. In that academy, teachers will teach you regarding Warriors(swordsman, mage, spearman, archer etc). They also teach blacksmithing and potion making. That school is the largest academy in the empire."

Zero nodded.

"Wait, is the empire at the south?" Zero asked curiously.

"Yes why?" Marco looked confused.

"Our luck is bad. The horde of monsters are in the south and now on their way here. It will be a battlefield tomorrow." Zero shook his head and sighed.

Maria and Marco has a troubled expression in their faces.

Zero sighed.

'Guess I have no other choice..' he muttered to himself.

"So I'll be staying with you guys for now is that okay?" Zero asked

The two nodded immediately.

"Maria you should always stay beside Marco. Immediately tell me if there is strange happening in your body alright?" Zero said while looking at Marco. He walked to Marco and place his index finger on Marco's forehead.

Zero's vision darkened for a while before he saw the demon inside Marco's body.

Zero's consciousness is now inside Marco's body. He saw the demon trembling before him while kneeling. The demon did not dare to breath loudly.

"Don't control this body without my permission. Or else you will face the consequences in disobeying my words."

Zero looked at the demon with a sharp gaze. After saying that, he returned his consciousness.

"You will be okay for the time being."

Zero said with a cold face then he removed his index finger in Marco's forehead.