They were something very useful, they prevented many scams during these years. The problem was that it wasn't directly accessible to everyone. Few knew the processes needed to manufacture it and of these, few had the skills to do so. Seeing the man sign the contract without throwing a tantrum, Han was a little less worried. Turning to Kayden, he pulled a box out of thin air. It had a polished wood material and was at least 1.5 meters long.
"Kayden, as you won't be able to train at the dojo, I decided to give you a small gift on your journey", saying that, the man opened the box. Inside was an 80 cm katana, its blade was black and seemed to be unable to reflect any light, its hilt was white and had a small golden ribbon on the tip. It was really impressive. Next to it was a scabbard of the same length in black.
"Its name is Abyss and it was made by a friend of mine," Han passed the gun to Kayden as he spoke. Its weight was beyond what Kayden expected, it was about 5 kg, five times the weight of his usual weapon. Looking at the base of the blade, he saw something written that caused a small shiver. It sounded like something a god facing Olympus would say.
"If the sky falls, I'll hold it in my hands", is a catchphrase.
"Thanks, Dad. I loved it and will make good use of it", Kayden was happy with the gift and hugged his father. Han was taken aback and didn't have time to return the boy's hug.
"Okay, now I'm off. If you need anything, let me know. I'll send the money for the tickets on weekends", Han quickly said goodbye to prevent the two of them from seeing him. Kayden's hug caught him off guard and resulted in a small spurt of embarrassment from the old man.
Seeing the man simply take flight suddenly left them both momentarily speechless. Until the silence was broken by David. While ruffling his hair, the scientist said:
"Come on Kayden, I fixed the basement for you." That phrase caused Kayden to feel a little apprehensive. The man was a madman, what would his hold be before? A place of torture? A prison?
Entering the house, they descended the same staircase that led to the second floor. As soon as he entered the basement, he saw that he couldn't judge a book by its cover. The room was clean and had gray walls, while the floor was smooth stone. There was a bed in one corner and a small table next to it. There was also a wardrobe on one wall, on another there was a shelf to put books and next to it a door to what appeared to be a bathroom. Placing the boy's bags on the floor, David turned to him.
"I'll give you some time to pack your things, take a shower or whatever, then go upstairs so we can discuss our project." David gave a crazy laugh, he looked so excited.
Once the man was gone, Kayden packed his things and put the books on the shelves. He took a shower to calm his body from the long trip and went upstairs. He found the scientist stacking books on the lab bench. There were at least a few dozen there and more on the floor.
"Are all these books about mana hearts?" Kayden doubted there was that much information on the subject. David stopped stacking the books and turned to the boy.
"Not all. Many here are about advanced mana manipulation, things you're going to need to learn if you want to be able to do everything we need to." David thought the second most difficult thing about this endeavor was the boy's skill and the first was the project itself.
"Sir David, please see if you can't find any books on the anatomy of the heart and how it works." Kayden presented his ideas. "We need to practice building it several times and if we know how it works better, we will have a greater chance of success."
"Well done boy, I hadn't thought of something as simple as that, but it really will make a difference. And please, just call me David. We'll be spending too much time together to waste time on mere formalities."
That day, the two spent the entire afternoon and evening looking at the books and debating the alternatives. David was impressed with Kayden's effort to do the rather boring part of the job and how the child had ideas and was able to discuss them maturely.
The next day, Kayden woke up early and was studying the books again. David was still sleeping. While the boy went to bed early and woke up early, the man worked late and woke up late. Around noon, Kayden heard the sound of someone coming down the stairs. When he turned around and faced David, he saw him holding a ball of yarn. The color was purple and it was bigger than a basketball. David finished down the stairs and came over to talk to Kayden.
"Good morning, Kayden," David yawned, looking like he'd just woken up. "I brought this magic item for you to practice." He passed the ball that didn't seem to have anything magical. "You must be imagining that it's an ordinary ball of yarn, right? But that's a silly mistake. If you feel the mana, you'll see that there's a small trail on each thread."
Kayden did as the man said and there was, it looked like a ball of mana.
"Good morning, David, what's this for?" Kayden was curious, what could he train with this?
Catching
the skein and demonstrating how to use it, David began to explain what it was and what its purpose was.
"This skein was made for children to practice mana manipulation. You must undo it without using physical touches, just guiding the mana threads to come loose", David began to disassemble the skein. "You must not have seen this as it was discontinued in the last century."
Kayden noted how difficult it was and required meticulous mana control to accomplish the task. Certainly, training with this skein would bring satisfactory results, but he was in doubt about why it was discontinued.
"Why don't we use this more in schools?"
"The process is slow and takes hours to train. Children don't have this patience when they are young and when they get older, they don't need it anymore. As you increase your rank, mana manipulation doesn't become as necessary. You already are capable of doing what he needs to do at a mediocre level."
Kayden quickly understood what David was trying to say. For most people who didn't have big goals, it was useless to train with the ball as it wouldn't help them momentarily. The ball was an investment for the future. Certainly, the great families of wizards forced all children to use balls of yarn from an early age.
"I'm going out to buy books on the anatomy of the heart. Good luck with your training Kayden, you're going to need it," the man had a smile on his face as if he'd been there before.
Taking the skein, Kayden began to try to unravel the threads and... failed. He hadn't expected it to be so difficult, each time he pulled one side out, the thread would wrap itself around another. He spent hours on it, he even forgot to read the books or do his exercises.
His fruitless practice was only interrupted when the front door opened and David came in with piles of books floating in the air. At that moment, Kayden realized that it was night and that he hadn't eaten even a grain of rice all day.
"David, what are we having for dinner?" Kayden's stomach found this the perfect moment to growl.
"I forgot about it," the scientist's stomach also roared in response.
In the end, the two had to make do with leftovers from David's last meal, the scientist didn't even know when it was.