In the end, Shiro ended up explaining how food needed to be digested and all before casting her healing spell.

She could cast the spell despite how tired she was.

But doing that would strain her body and potentially shrink her muscles while also risking organ failure to happen.

And since her body was fine and she only lacked vitality, it was much harder to recover with magic with her body in such a state.

Danzel was somewhat knowledgeable of this fact too, so he simply nodded at her.

He remembered reading in one of Velkir's books of necromancy went about how repairing an undead body wasn't as efficient as the living.

Which made healing skills for the undead quite taxing in mana.

But on the plus side, compared to that minor weakness, they didn't have to restore flesh like the living, which cost mana too. At least that was the case for the skeleton-type undead.

He didn't know how it worked on other undead like ghouls or ethereal undead.

Understanding her point nonetheless, he waited for Shiro to finish eating before talking about her certain condition.

And she eat...a lot more than he expected.

Though she was first hesitant to try this white liquid, she seemed to enjoy it to the point she asked even more. Albeit, that was all the "milk" that he found in this village, which after sharing that news made her sulk a bit before finishing her meal.

'Or would a feast be more appropriate?' Danzel thought before shaking such useless thoughts away.

'If I remember right, the comes from that big animal that I killed before, but where it comes from...' Danzel had no idea.

He tried to remember if there was some of that "milk" when he butchered that animal, but no memories came to mind.

In the end, he shrugged it off and focus on Shiro who was finishing her "feast" with the last remaining milk in a wooden cup.

"Haah~delicious," Shiro said with a satisfied grin as she put the cup to the side while above her limps were still bits of milk being there.

"Alright, I am done. What do you want to know about?" She said while focusing on Danzel.

'...'

"...I want to know why you have the such condition and how you got it. Also what exactly triggers a such reaction in your body."

Shiro put on a thoughtful and serious expression as she touched her chin with her hand, which with the milk above her limps make her look quite silly despite how serious she looked.

"Alright, I will tell you." Shiro nodded her head.

"..."

"Though to be honest with you, I don't know why I have such a condition. All I know is what my grandpa told me, as I was too young when I received this...sickness. I-"

"Wait there, received? So you weren't born with it?" Danzel asked.

"Eh? E-Ehm...apparently I wasn't born with it, at least that's what my grandpa told me. When it happend I was way too young to remember...around 3 years old? Unlike humans, we Nagaiki Oni live much~much longer than them." She said while lowering her head to look at her long hair and nails.

"We also grow faster in our early years till we first reach adulthood. According to grandpa, we become an adult when we reached 35 years of age as that's when our hastening to grow stops and our total lifespan is around 500-1500 years, if not more, grandpa told me that it depends on how much we can extend our horns, but that isn't the case for Shiro..." She said while letting her hands fall to the bed on top of her hair.

"Because of my condition, my body grows much faster than those of my race. I am only 13 years old and yet my body is that of someone above 25 years..." She said somewhat depressed.

'A lifespan of potential 1500 years and possibly more... not better than my immortality, but compared to humans, that's an awfully long time. And with the information coming from Agares, then he possibly could be more than 1000 years old. Not as old as Velkir I guess, but still...'

Though it was quite surprising, it wasn't mind-blowing to say the less as he knew beings that were immortal just like him.

But even then, he could understand as of why those with finite lifespans would be discouraged by them growing faster. As he knew what came after death.

'It also explains why Agares sought out Velkir in the first place...'

He always wondered why Agares started doing mercenary work when he clearly didn't want Shiro to get dragged in.

'He must have asked Velkir for ways to fix it and considering that I saw it happend, there must be a treatment, but no cure...' Danzel despite connecting the dots, still wanted to hear it from her.

"If I am not wrong, Agares and you went seeking help from Velkir, though seeing you still have it, there isn't a cure, but there is a treatment, right? Do you know what it is?"

Shiro shook her head.

"No, I don't know. Master Velkir said that he manipulates my mana without using any of his own to delay the sickness from happening and lessens the pain. But I don't know how he did it..."

"I see." Danzel nodded his head in understanding.

'In short, we are screwed.'

Although what she said was simple enough, actually doing it was hundreds of times harder.

Manipulating mana that was everywhere and manipulating mana that was owned by someone else while inside their body?

Even he couldn't do it.

Maybe he could make a change if he used his own mana to go inside her body and forcibly move her own mana, but that by itself would be extremely hard to do and harming by itself for many reasons.

And she is talking about doing this exact thing without any usage of mana?

Impossible.

At least for him, it was impossible.

'That means that I will have to gain more of that troll blood for just in case her talents try to kill her again. Despite how inefficient I am using the blood...'

"I understand your current situation and I can think of a few ways so that you won't die, but as for the pain..." Danzel shook his head.

"In any case, how did you receive such...sickness?"

"My grandpa told me that a wave of mana hit our village... and that I and grandpa are the only survivors, with me getting this sickness. At least that's what he told me, I-I was too young to remember. Mostly it happens when I use mana, but it also can happend randomly, I-I don't know what causes it..." She said, her voice growing more depressed.

Seeing her mood, Danzel decided to call off his questions for today.

"That should do it for today. Can you walk?"

Shiro tried, to get up from the bed, though her whole body ached in pain before deciding to give up.

"It hurts..."

"I see...I guess we will wait a few days till you recover before leaving this village. For now rest." Danzel said while going towards the door to leave.

"W-Wait Rue!" Shiro said accidentally too loud.

"What?" Danzel turned his head around, his flaring dark green eyes glaring at her, his eyes showing little to no emotion.

"E-Ehm...you see, would it be possible to...like, borrow one of your books while you are not here? It will be quite boring if I lay here all day..."

With her request, Danzel stayed silent as he thought of something.

"I-I promise that I won't damage them the slightest! I will take care of them!" She said nervously and yet full of determination.

Danzel found it quite ironic how she, who loved magic to this extent, has her lifespan reduced by the source of magic itself.

Honestly, he didn't like the idea of giving his books to her unsupervised, as those were extremely valued items to him.

But remembering the Anabast that he summoned, an idea of an experiment crossed his mind.

'What if they are able to learn? The content of those books?' He thought internally.

Not only did they have the [Magical Talent] talent, but they also had a various amount of affinities. Their intelligence attribute was also high. Although those numbers didn't display how wit or clever you actually are, they improved the efficiency of one's mind by a lot.

Though it went till the 3rd-tier those books, the Anabast were of the 3rd-tier too. Once the idea sprout inside his mind, he wanted to test it, but Velkir told him once not to spread such knowledge willy-nilly or those he doesn't trust.

But as the Anabast was essentially bound to him and had a connection with him, he guessed it would be fine to share Velkir's knowledge with them.

Though for that, he needed multiple books and not just one set.

And looking at Shiro, he brought out all his books of magic except the one of Nersanrah and placed them at Shiro's side.

"Sure, but you will have to do something for me in return. Just like our previous deal." Danzel said in his cold voice.

Shiro looked at the books in fascination before remembering Danzel's words, making her face turn serious as she remembered that nothing was free with this petty undead.

"What will that be?" She said while looking at Danzel with suspicion.

In the next moment, Danzel brought out all his remaining rune contracts, which were stacks of papers.

"It's simple really, you just have to help me make some copies of those books."

Though using the runed contracts could be considered wasteful and would essentially exhaust most of his supplies of paper, Danzel decided to use them regardless just to honor Velkir's wish.

And make sure that other than them, no one will get to see the content of those books except their owners and the creator himself.