“What is a blood oath?” Red asked.

“Y-You don’t know?” The merchant was taken aback. “I-I mean, it’s a way to bind my lifeblood to an oath! If I break this oath, t-then my lifeblood will wither and I will die!”

“I see.”

With this explanation, Red understood it a bit more. He heard of these types of oaths before, but these were made through contracts or other divine powers. This was the first time he heard about one made with blood.

“I-If you’d like to, I can explain the steps to you myself!” Emer bowed his head at the youth.

Red didn’t respond, instead extending his hand into his pouch once again and grabbing the crystal core.

“Is what he’s saying true?” He asked Aurelia.

“It is.” she said. “Plenty of sects make their members swear oaths, but only demonic cultivators swear oaths through their blood.”

“Why is that?”

The woman snorted. “Because it’s blood magic, of course. A simple one, but still blood magic.”

“What are the dangers to it?”

“In the method itself? None really. Other types of oaths will kill you if you break them the same way. The only problem is that every oath has an overseer…”

“An overseer?”

“Yes. The oaths aren’t kept by simple magic, but through the safeguarding of a greater force.” Aurelia said. “Whether it is a god, a sacred spirit, or even a law of nature, this greater force has to agree to safekeeping this oath. It’s why people only swear oaths in the name of deities related to law and fairness, whom they know will uphold it no matter what happens. In the case of a blood oath, though…”

“He will have to swear an oath to an archdemon?” Red finished her thoughts.

“Correct. Most archdemons wouldn’t even bother responding to those though, unless it’s related to a worshipper or someone they find worthy.”

“… I understand.”

With Red’s experiences with archdemons, he wasn’t too confident in their response to an oath involving him, and neither would he trust them with it.

He retracted his expanded awareness and looked down at Emer. “You want to swear this oath to the Infernal Emperor?”

“W-Well, yes, my lord.” The man nodded. “I-I wouldn’t be able to do it to any other deity.”

Red frowned. Even if the oath worked, how could he be confident this unknown deity would punish their own worshipper if they broke it? He just couldn’t count on it.

‘It seems in the end I have no choice but to kill him.’

Right as Red was thinking that, he felt something within his body. A familiar sensation in the pit of his stomach, as if something was calling to him.

The crimson mist.

‘What does it want?’

The moments during which the being within his body called out to him were rare, much more so after the accident during the Full Moon. The fact it called out to him right at this moment made the youth alarmed.

He entered a meditative state on the spot and reached out towards it. The crimson mist was trembling in the pit of his stomach - a state that meant it wanted to communicate with him.

Red used his thoughts to convey his words. “What is it?”

“Oath…” A faint voice reached his mind. “Swear… To me.”

The youth frowned. As far as Aurelia told him, blood oaths needed to be sworn to archdemons, or at the very least, existences on their level. Whatever the being in his body was in the past, now it was reduced to a small presence in his body, so Red didn’t think it could uphold an oath like that.

“You’re too weak.” Red said. “Can you really keep an oath?”

The mist quivered again. It showed some anger at his question.

“Blood…” It said. “Feed him… Blood.”

“Just like that?”

“Yes… Feed him… Loyalty will come.”

Red frowned, but he knew an explanation wasn’t forthcoming. He never managed to hold a full conversation with the being before, anyway.

He retracted his expanded awareness, reflecting on the conversation he just had in silence. The merchant continued to shiver on the ground. It seemed with each passing second, he was losing his hopes for remaining alive.

‘Fine.’

After some hesitation, Red decided to follow the mist’s advice. He needed someone with knowledge of cultist matters to accomplish his plans in the city, and the merchant was the only choice he had at the moment. The only way the youth could rely on him, though, was if he was certain the man wouldn’t betray him.

Of course, he knew the crimson mist probably had some ulterior motives for this. In the past, it had refused to offer him help even when his life was at risk, so why would it do it now? Whatever the case, though, he thought that whatever it had in mind wasn’t against his best interests.

As if feeling his approval, Red felt a force travel up to his right hand and into his index finger. The youth placed his finger against the edge of the blade before making a light cut. Some droplets of blood started to pool at the tip of his finger, though it didn’t drip down to the ground, instead accumulating into a small blob that remained still against gravity and common sense.

Red looked down at the merchant.

“Drink my blood.”

Emer looked up at him with a look of confusion.

“What the hell are you doing?!” Aurelia’s alarmed voice reached his ears, but the youth ignored it.

Red ignored her, gazing at the merchant in silence.

The merchant shivered under his icy stare, and he looked at the blood on the youth’s finger with some hesitation. Still, with a fearful expression, he extended his hands to grab the bloody finger.

Red frowned at the strange sight, but he didn’t pull his finger away.

Before the merchant could drink the blood, though, the droplet moved as if it had a life of its own. It shot towards the merchant’s mouth like an arrow, causing the man to choke.

Emer fell to the ground, his hands reaching towards his throat as his breathing was seemingly blocked. His eyes looked around in despair, but he was helpless to do anything about his situation as this demonic blood did something to his body.

Red himself also felt a strange sensation. It was as if a part of his being had split from him, fighting against an enemy he could not see with the merchant’s body as a battlefield. Despite this feeling of connection, though, the youth didn’t feel like he could influence this battle.

Someone else was fighting in his stead and, by the looks of it, they were winning.

The merchant’s struggles started to die down, and he seemed to recover his breath. Red also felt the fight end with the victory of his blood, and an unseen connection was formed between him and this merchant. A sensation of dominance, as if Emer’s life was at his whim. He couldn’t tell where this bond was formed and how he was supposed to exert his influence over it, but he supposed he didn’t need to concern himself over it.

The crimson mist was the one overseeing it, after all.

Emer also seemed to feel this connection, and he looked at Red with an expression of fear and reverence. He bowed towards the youth on his knees, his head hitting the ground with force.

“This servant greets his master!”

The man didn’t express any resentfulness towards the youth. It seemed as if being allowed to live and serve another master was the greatest gift Red could grant him.

“You… How did you do that?” Aurelia sounded confused.

Red once again ignored her question.

He looked at the old man. “I hope you understand that this is not an oath with conditions and loopholes. As soon as you betray me or do anything that can be interpreted as going against my interests, you will die.”

Of course, what Red had done didn’t feel like an oath at all, but more like a kind of enslavement. The fiend was the one overseeing this “contract”, so it could act as it pleased without concerning itself about conditions or circumstances if the merchant betrayed him. At least that’s what the youth was hoping it would do, considering that if his demonic identity was revealed, it wouldn’t benefit the mist either.

Emer nodded. “I understand, master!”

The youth was satisfied. “You can get up.”

The merchant did as much, only now realizing with a disgusted expression he was kneeling in the pool of his brother’s blood the entire time. Still, he didn’t move away in a panic, waiting for Red’s command.

“This maid of yours… Will she be a problem?” Red asked.

“A-Ah, you don’t need to concern yourself about her, my lord!” Emer shook his head. “She’s not really alive.”

“Not alive?”

“W-Well, her body is still alive, but her soul is long gone. She is no more than a puppet that follows orders of the master of the house.”

The youth frowned. “How did that happen?”

“I-I’m not too sure. She was a gift given to my brother by one of his comrades, and all I know about her is what he told me.”

Red couldn’t detect a lie from the merchant’s fluctuation - not to mention the old man couldn’t lie even if he wanted to. He could only guess some sort of demonic method was involved in transforming this woman into a living puppet.

“Does she leave the house?” he asked.

“No, my brother doesn’t… didn’t allow it because of her strangeness.” Emer shook his head.

Red recalled her impassive face while greeting him at the door. “Will she listen to my commands?”

The old man hesitated. “… I-I can’t say for sure, but my brother made sure she would listen to all my commands.”

The youth frowned. “Can she speak to others about what happens inside the house?”

“N-No, my lord! Even if I commanded her to do it, she is incapable of having a memory.”

Red supposed that this was true. A soul was made up of both consciousness and mind, and without it, one wouldn’t be able to store any information in their brain.

Still, if she was unable to store any information in her head, how was she still able to follow commands as a puppet? Red wasn’t too sure about how those arts worked, and as such, he considered whether it was worth the risk to keep this woman around.

‘I can ask Aurelia about this later.’

If she still wanted to talk to him after he ignored her questions two times in a row, that is.

Whatever the case, it was unlikely the maid would become a problem at this exact moment. Red instead had more pressing concerns.

He looked at Emer. “Tell me everything about this cult of yours.”