To be honest, the loss of mana has been present since the moment humans learned to use spells, so mages have long been accustomed to it, and no one usually delves into this aspect at all.

After all, the loss of mana is almost every mage, and it is nothing more than a matter of more and less, so unless the foundation is too poor, and the guy who can launch the same spell with twice the mana of ordinary people, or the poor who are really loud and care about the durability of the magic weapon very much, basically will not care about the loss.

But Joe noticed it.

He found that although the mages didn't waste a lot of mana every time they cast a spell, if they accumulated it many times, the amount of mana wasted was actually quite amazing! So sometimes it's clear that two mages with the same talent, but the one with good spell casting habits will often perform better, giving people the illusion that they are more talented than the other mage

So from that time on, Joe was quite concerned about this phenomenon. Because he knew very well from the beginning that he was not a gifted person, although he was also excellent, there were people in the War College who were even better than himself, so he was just a very ordinary one in the War College; And Joe doesn't have a physical advantage like Xia Zuo, and the level of hand-to-hand combat is honestly average, and in the collective of Crouching Tiger, Hidden Dragon, Yinyue, he can only be regarded as a middle and lower, except for Nina, a small body that no one can beat, Joe feels that he may not even be sure of winning Pei Ji's non-stop chattering all day long, so he can only find a breakthrough from other aspects for this guy who has high requirements for himself.

By chance, Joe gets a peculiar piece of ore and discovers the wonders of it. So he asked Nina to polish the stone into a more common form to test the loss of mana when he cast a spell. As long as this stone is installed on the top of the magic weapon, then once the spell is cast, the luminous degree of the ball can intuitively reflect the consumption of mana. The brighter the orb, the more additional mana the mage consumes when casting the spell, and vice versa. It can be said that this peculiar ore is very suitable for training mages' casting habits, and the effect can be seen directly with the naked eye.

At this time, Nina spoke: "Because his parents have been strict with him since he was a child, Joe's spell casting habits are already better than most of us. In addition, he has liked to study the magic circle since he was a child, so it didn't take long for him to be able to make the stone not shine at all in the actual combat process. Joe hadn't changed his magic weapon since, and his staff was still as good as new after years of use. ”

An An suddenly realized: "No wonder I felt something strange when he played in the team game before, but I couldn't say it for a while." Thinking about it now, I'm afraid it's because he was obviously casting a spell at that time, but there was no trace of the basic magic circle being activated on the magic weapon, so it gave people a sense of disharmony. ”

Nina nodded: "Yes, in order to ensure that the spell can be cast successfully, the average mage will often allocate more power than required on the magic circle, and the extra part of the mana will make the basic magic circle glow, and this is often considered a sign of successful activation of the spell." But in fact, as long as the distribution of power is precise enough, it is possible to prevent mana from being lost in the form of light and heat. ”

Charlene also understood: "I see, no wonder you think this thing will suit me." ”

Although in the end, Joe left the big one for Nina and only took the small one himself, but it was really useless for the big one to stay with Nina.

Because Nina's magic weapon is fundamentally different from other mage's magic weapons, you can obtain a complete comprehensive magic circle by changing the form of the magic weapon. So strictly speaking, Nina's spell casting technique is closer to casting spells directly through the circle. And the biggest feature of directly casting spells through a complete magic circle is that there is no loss of mana in this process, so the function of this stone is simply a number of moves for Nina, which is really chicken. And a talented guy like Lin doesn't care about the extra bit of mana consumed at all, so this stone is of little use to him; As for An'an, there are obviously more options that are more efficient and more rewarding. So looking at it this way, it is true that only Charlene can use the ability of this stone.

Since Charlene has not been studying the use of witchcraft for a long time, her spell casting techniques are still a little immature, and she is not so skillful in control, and occasionally she even misses.

This is mainly because the casting effect of witchcraft is much stronger than that of spells, and the casting range is also greater than the effect range of spells, so it is easy for people who are originally mages to confuse the characteristics of the two when they first come into contact with witchcraft, resulting in misjudgment. In addition, many witchcraft mastered by wizards pay great attention to the accuracy of witchcraft control, and it is easy to cause large-scale explosions and poisoning if they are not careful, so in order not to hurt themselves and the innocent, a qualified wizard must be quite sensitive when performing witchcraft, otherwise it is easy to be counterattacked and even hurt himself. Therefore, wizards need to be able to manipulate their mana quite accurately, and then combine it with witchcraft to achieve the most perfect effect, which is what Charlene lacks the most now.

Although Charlene has always received an elite education typical of aristocratic families, and her methods and habits of witchcraft are also neat, these alone are not enough to master witchcraft well. So even if she goes to the battlefield, Charlene will only use some crude witchcraft now, most of which are types that do not require the dosage and range of witchcraft very precisely, so it is indeed appropriate to use the ore ball that Joe left for Nina to train Charlene on how to correctly control the size of her mana.