He set the wand aside and selected another one. This time the gauntlet glowed blue as he scanned more than just its physical composition. Data rolled through his mind and he couldn't help smiling to himself, "I was right! The faith system is significantly more restricted. Not only that, but the requirements to unlock even pre-programmed forms is significant."
"Ah, I see. Evolutions are locked behind the Scale Mail! Clever. Using a dragon's full might requires a dragon's body. The Scale Mail is the closest a human could get so locking potential evolutions behind it is a must! Until then there's a hard limit on what can be unlocked and achieved to protect the user. Though..."
He frowned as he double checked a section, "Ah, it's possible to override the safety with a powerful enough 'need' to do so. The price is steep though."
He continued to scan the faith system and pondering to himself. It was very similar to the system in his Sword Birth, but it had multiple layers of safeties built into it that strictly limited the power the Boosted Gear could give to the user. All of the safeties were based on the user's personal condition.
He could also see how some of said safeties could be overridden by Ddraig taking a part of his partner's body and turning it into a dragon part. It wasn't so much Ddraig 'wanting' the part as it was the new draconic part giving the user the necessary strength of body and 'belief' to work with a normally locked aspect of the gear.
Case in point, Issei 'giving up' his arm to Ddraig to use Scale Mail against Riser for a few seconds. The draconic arm boosted Issei's vitality and allowed Ddraig to override the safety. As for it only working the one time... Overriding the safety like that dealt damage to the user. It wasn't so much that Ddraig couldn't override the safety, but that he wouldn't. He also guessed that was why Ddraig only let Issei use the Scale Mail for a few seconds, to minimize the damage and risk of death.
There were other subtle nuances, but they seemed to be more specific case scenarios. There was even one for just in case Ddraig somehow managed to sneak his soul out of the Boosted Gear.
Junichiro started to cycle through the various wands he collected, each causing the gear to glow a different color. Each gathered information on different aspects of the Sacred Gear and helped fill in a complete picture of it and all of its functions. He scanned it so thoroughly that the only secrets it still held were related to Ddraigs soul and memories.
With most of the scanning done, he picked up the last one. This was one of his most recent creations, a wand specifically designed with a spell to scan the details of the targets soul. He'd made it in order to scan his soul completely and used it to constantly keep an eye on it. He didn't think anything could go wrong with Sword Birth, but he wanted to be on the safe (paranoid) side, just in case.
The wand tip began to glow with a silvery-white light that soon surrounded the gauntlet. As the spell sank into the gauntlet, it let out a pulse of power that broke the spell. The next moment the green gem on the gauntlet flashed as a deep masculine voice echoed out of it, "Hm? Ah, my new... wait... Why am I not within my new Partner?!"
Junichiro hardly blinked at the result of trying to scan Ddraig's soul within the gauntlet. He'd expected something like this could potentially happen. He'd hoped it wouldn't, but there was nothing he could do now that it had. He set the wand down and addressed the gauntlet, "Welcome to the waking world Y Ddraig Goch, it's an honor to meet you."
He wasn't sure how, but he was certain that the unmoving, unchanging, green orb was somehow looking directly at him, "Who are you boy and what happened to my partner?"
"I'm Arai Junichiro. As for your partner, I removed you from him."
"Did you now? So you killed my partner and stole me from him before he even awoke me. Why have you done this, coward?"
Junichiro blinked and processed that for a moment before sighing, "I see. First and foremost, I didn't kill anyone. Come to think of it, I've never killed anyone and the only fight I've ever really been in cost me an arm. That's beside the point though. Point is, he's still alive. I'd have fought him for you but... well, he's just an incredibly pathetically weak human. Hell, he only has enough mana to qualify as a living being!"
"... I see. And what, you believe yourself worthy to be my next wielder?"
"Eh, I don't know about worthy, but I do know I'm a significantly better option than that guy. I mean, unless you want to be stuck inside of a weakling human with an obsession over mammary glands and building a harem of women."
"What?"
"Oh yeah. The guy you were inside of is a complete and total pervert whose only real ambition in life is to build a harem of pretty women so he can worship their breasts. I mean, I think he's a worthless waste of oxygen but, if you're that desperate to be partnered with someone who was chosen at complete random that you don't even know... Well, I could always put you back inside of him. I'm sure you'll awaken again in a couple of years. Just don't be surprised if it takes him a dozen boosts to match a Mid-Class Devil."
"I think I'd rather not. However, " His voice deepened and became oppressive, "That doesn't mean you're worthy."
"True, true. However, I know things that I think you should take into account."
"Hoh?"
"Mhm, for example. I know about your rival and his current host. Interested?"
"What do you know?"
"Lets start with some basics, like his name! His name, is Vali Lucifer."
"Lucifer?!"
"The original is his great grandfather. His mother was human, making him a half-breed and granting him a Sacred Gear, Divine Dividing. So, your eternal Rival is now inside of a being with a natural lifespan in the thousands of years. Meanwhile, you were stuck inside of a pathetically weak, even by human standards, boy with a lifespan that might surpass a century. Provided he didn't instantly die the first time he encountered another supernatural."
He had to toss the last bit in because canon Issei had, in fact, died to the very first supernatural he learned of.