Then there was Vali's situation. While he did grow stronger over the course of the canon story, his growth wasn't all that much, comparatively, to Issei's. If Junichiro thought about the faith system, this also made sense. A major driving force for Vali was his need, his desire, to kill Rizevim. Now, this could give him some growth, and likely did leading to Vali being as strong as he was in the beginning of canon. However, Vali would also be aware of Rizevims Sacred Gear Canceler, meaning his faith in Divine Dividing would never be as high as possible due to unconsciously knowing, and fearing, that his Sacred Gear would be useless in his penultimate fight. Thus, less faith to empower it and slowing his growth.
It was just a theory, but from everything he could remember it made sense to him.
This meant the way to truly have a powerful Sacred Gear was to have complete faith in it. To know, with every fiber of your being, that it would serve you in your purposes. To practically worship it as one would worship the God of the Bible.
Man, that guy really was big on the worship.
The last thing he'd been able to determine wasn't all that important, really. Just that the amulet was made from a dragon scale. He had no idea which dragon and couldn't tell much more than that the dragon was strong enough, and large enough, that the amulet had been made from a single scale. Likely at least as strong as a Dragon King. He highly doubted it was one of Ddraig or Albion's scales though.
Now he kind of wanted to get his hands on a Twice Critical to see if they were made from Ddraig's body since they had his iconic Boost, even if it was limited. Not to mention it'd be nice to make items with a similar ability. He could make 'buff items' but they were always one use items, such as potions. Repeatable buffs would be nice.
Junichiro shook his head and stood up to return the wand he'd used to the wall and selected another. He used the new wand to perform another type of scan on the Sword Birth Sacred Gear to see if he could glean any more information. Sadly, all he found was a link heading off into the distance. Judging by what he knew, he expected this link was the link between Sword Birth and the Sacred Gear System designed by Big G. It seemed a little too weak, probably a result of how it was removed from its previous owner. His best guess was that the link would reestablish once it was back inside of a human, such as himself.
He performed a few more scans but didn't really glean anymore information aside from how he could expect the Sacred Gear to work once it was within his soul. He'd have to actually use it to know if his deduction was correct. After replacing the last wand back on his display, he crossed his arms over his chest to stare at the object of his desire. Part of him wanted to keep it out so he could study it more in the future. The other part wanted to jam it into his chest and begin experimenting with it.
…
He grabbed the medallion and held it to his chest while channeling his magical power into it. The medallion immediately began to glow while it seemed to convert into energy that moved into his body. It wasn't uncomfortable and, in fact, felt pretty nice. Since he hadn't been born with it and was more aware of his body, magic, and soul than most beings, he immediately felt the Sacred Gear settling within.
When the light show died down, he smiled. He knew if he didn't install the Sacred Gear now, he'd never install it. He would procrastinate and delay until it was far too late to do anything useful with it. Despite that, he got plenty of good information from his scans and a few concepts and ideas to add to future projects.
Once he felt that Sword Birth had settled into his soul, he focused on it and began feeding magical power into it. He stopped when he felt... emptiness. There was nothing within it, meaning no sword designs. Okay. He could change that. He closed his eyes and focused on picturing a perfect single handed English long sword. He imagined it with a double edged blade leading up to a sharp point with a fuller going up one third of the blade, a slightly curved and unadorned cross guard, leather wrapped wooden handle, and circular pommel. It was a simple, yet highly effective, sword design that had proved itself over the ages.
With the sword image firmly in mind, he fed magical power into Sword Birth once more and smiled when he felt it 'click' together. With a flash of white light he was holding the exact sword he hand imagined in his hand. With the sword manifested, he immediately used his Artificer ability to scan item with his magical power to get some information from it. He was pleasantly surprised when it came back as a basic steel sword. If it wasn't for one single factor, he wouldn't have been able to tell it was a conjured item. The best way he could describe it would be to say the sword's existence was 'thin,' for lack of a better term.
It just meant the sword would likely shatter after exchanging a few blows with a real sword if any real power was put behind it. In his estimate, someone with regular human strength using it against a regular human strength opponent, would never shatter it.
He slowly worked through a few katas, forms, with the sword in his hand and noticed things he hadn't consciously thought about were included in the sword design. For one, the balance of the blade was perfect. For another, it fit into his hand as if it were designed exclusively for him to hold. His grip on the blade would be very unlikely to falter. He also realized he'd never specified the material the metal should be. It was possible the default was steel since that was the best material for a simple basic sword by far. Exotic magical materials not being considered.