"Direct control over Dragon Veins' mana!?"

  "You'd be really strong if you could do that…"

  "Yeah. Strong… And on top of wielding unlimited mana, it's also possible to inject your mana into Dragon Veins' to cast magic through the veins."

  Having Dragon Veins connected to your magic circuits means turning the veins into part of your body.

  Hence, you can cast magic through Dragon Veins.

  …Of course doing so is incomparably harder than casting magic with your own body.

  "Through Dragon Veins… Is it like when I cast that augment magic that one time!?"

  "Yeah close enough. But since it's a direct connection between Dragon Veins and your magic circuits, using your mana to control it… done right, it can be way more flexible than that… It's like having the entire lands as your weapon."

  Hearing that… Alma's eyes are beaming.

  "Awesome! Sounds so strong!"

  "But… Considering it's got the name 『Man-eating Blade』, there must be something more to it than just strong right…?"

  Ruli asked with a worried look.

  …Then too Alma seemed to realize the risk.

  "I mean, can human's magic circuits even be connected to Dragon Veins safely?"

  That's exactly the problematic point with [Man-eating Blades].

  Difficulty to control mana or low quality and such are problems that crop up only after your magic circuits have been connected.

  The mana flowing in Dragon Veins… vastly dwarfs that of a human's, even before we get to quality and stuff.

  As such, even if you're paying close attention to prevent mana influx, you still need extremely durable magic circuits to bear such power.

  And even people who possess sturdy magic circuits would easily get swallowed up by the vast mana were they even slightly let their guard down.

  During the era I lived in, there were casualties by [Man-eating Blades] practically every month.

  The power contained in Dragon Veins was just that tempting.

  The swords which were initially called [Dragon Veins Blades] received the name [Man-eating Blades] during that period of time.

  As I reminisced the past… Grevil opened his mouth.

  "Of course it's not safe. Those abominable swords claimed countless lives during the era I lived in."

  "Wait, you're saying 『Man-eating Blades』 were present during Grevil-san's era!?"

  "Yes. Or rather, those swords only existed in that era… I have no idea how Mathias-san came to know about those swords… But since they were quite famous back in the day, it wouldn't surprise me if records of them remained in some documents."

  Grevil explained and covered for my knowledge about the swords.

  Then… Grevil turned toward me with an apologetic look.

  "Mathias-san, to tell you the truth… There is only one 『Man-eating Blade』 remaining now."

  "Eh?　…Weren't there tens of thousands of those swords?"

  『Man-eating Blades』 were a very popular weapon during my era.

  After all it enables one to wield enormous amount of mana for free.

  It's got its risks, but since risks naturally come with battle to begin with, many people didn't care about it.

  As such, in its heydays, around 3000 [Man-eating Blades] got mass-produced every year, it was said that there were around 50,000 of those swords in the whole world.

  Since the swords were still being mass-produced when I reincarnated myself, the final number should be even higher than that.

  And yet there's only one remaining?

  "Indeed… There were tens thousands of those swords during the height of popularity. However, presently there is only one remaining… Although there might be other swords that I'm not aware of."

  "Was there some kind of incident?"

  "Rather than incident… There were just too many accidents. The mortality rate of swordsmen who employed [Man-eating Blades] climbed up to 25 times of magic combatants who didn't. As I could not overlook the ever increasing numbers of victims… I decided to ban the production of the swords and destroy all the existing ones. It was me who issued the order… My apologies."

  I see.

  So that was why I couldn't find even one of those hugely popular swords with Active Material Detection.

  Ugh why'd he do that… the thought did cross my mind for a bit, but he did the right thing as a king.

  The mortality rate of that sword users was abnormal indeed.

  A king who would look the other way at the huge amount of casualties for the sake of national power… would probably ignore it, but Grevil was a kind king who valued human life.

  That he couldn't overlook the ever increasing number of victims is probably true.

  "What about other countries?"

  "Other countries did keep using [Man-eating Blades] for a while… But once they realized that those swords were responsible for reducing magic combatants' numbers, which harmed national power, they abolished it as well."

  I see.

  In the end those swords were disposed of as good for nothing huh.

  Well, [Man-eating Blades] are not especially powerful weapons for sure.

  There are ways to cast high-powered magic even without enormous mana anyway, and those swords are more suited for inexperienced magic combatants trying to push themselves beyond their limit… something like that.

  There were occasions when I employed those swords myself, but once I had amassed enough mana and usable magic, I was actually stronger without that sword.

  Must be also why past countries rejected [Man-eating Blades].

  But I need this weapon now.

  Our opponent, the demon won't wait for me to get stronger the honest way.