kanzaki statement

[(...What's the real form of...that power...?)

Kanzaki spat out some blood as she wondered.

Having used all the power in this body of a Saint to use this spell called ‘Yuisen’, Kanzaki understood that a Saint’s attributes far exceeded what a human could do. ‘Yuisen’ had originally been created as a one-strike sword technique. If she didn’t do it like this, she may end up destroying her own body.

But Acqua broke through this impossible possibility front up.

Thus, he could pull the distance between himself and Kanzaki.

(—I don’t have…enough power to exert magic…on ‘Yuisen’.)

This spell wouldn’t just increase movement, it also prevented the muscles from exceeding what humans could endure and get destroyed, making sure that while the speed drastically increased, the entire body balance wouldn’t be lost. This was a ‘crystallization’ of all sorts of spells. If one wanted to go even further than that, or add in something else, the balance between all these spells would break down. Using the current pieces and piecing them together like a jigsaw puzzle, it was impossible to add a new piece in.

This was the limit of a Saint who mainly used close-ranged combat.

Maybe Acqua had some body defense spell that was even more refined than this.

Though Kanzaki thought of a few possibilities herself, no matter what, she failed.

As expected, there would be a problem if she powered up to his level. If she used a similar power to that of Acqua’s. If anyone tried to use the power that Acqua used, at that moment, an ordinary person’s body would have eroded, whether physically or magically.

(Acqua’s…power is…)

Normally, the power given to a Saint couldn’t be used entirely.

Since they were people who had similar body characteristics with the Son of God, Saints were those who were said to have inherited his power; even if it was just a part of it, in the end, it was not something that a human could grasp.

They had a part of that power, but trying to grasp a part of that part of power was already tough for a Saint.

This was the real identity of a Saint.

No matter how they built this up, there would be a divide that they couldn’t surpass. If one had to describe it, it would be like finally getting hold of a power only for it to scatter like fog. Thus, there was a limit to using the power created through the Idol Theory with their own willpower.

However, this wasn’t completely bad. If Saints could use such power at 100%, the high pressure would cause the Saint’s body to self-destruct. This was more of a self-defense instinct than magic, since when they were babies, they controlled that power without knowing anything about magic.] - Toaru Majutsu no Index Volume 16 - Chapter 4: Who is Protected by Whom? Leader_is_All_Members. Part 2