"Vincent, come over too!"

For the little fan brother who was probing his brain on the side, Xia Duo simply called him along, since there was one more Belera, he didn't care about another one.

Although the so-called joint operation refers to the joint operation of the Gilles Tower and the Gustav Tower, it is also a joint operation for individual participants.

Since Vincent already has a tendency to take the initiative to get closer, it would be too impersonal to refuse directly.

In comparison, Vincent's mid-level mage mixed in with three high-level mages may be more risky.

The only concern now is whether Vincent can understand the impact of plane differences on spellcasting, not only Xia Duo thinks so, but Nia and Belera also cast suspicious glances like Vincent:

"Do you know how?"

Targeted by three high-level mages, Vincent hurriedly replied, "I know! My father had already taught me before I came! It's true! I promise! ”

"Then start with the spells in the spell book! As much as you can verify, you can count as much as you can! Xia Duo directly set the task.

The spell book that I just received from the quartermaster is a magic item, although it is not as sophisticated as Xia Duo's spell book, but it is not so easy for ordinary mages to obtain.

However, considering that the participants in this mission are either pioneers or direct members of the Seven Towers, their net worth is naturally different from that of ordinary mages, and this spell book is actually just like that, but-

The real purpose of this spellbook is not just a semi-consumable item like a rechargeable scroll, but rather a syndicated spellcaster.

As soon as he received the equipment and supplies, Xia Duo checked them all, especially the equipment that was almost unnecessary to configure such as spell books.

"The Point Guard Is Here"

After a closer look, coupled with the comparison with Nia, Xia Duo made an amazing discovery-

That is, these spell books may have been set up with some kind of co-frequency function at the beginning of their creation, which is almost a natural joint spell casting prop.

Co-casting, also commonly referred to as synergistic resonance, is a way in which many Mentors exploit their apprentices' casting energy.

But the reason why it is called synergistic resonance is because different casters are essentially different subjects, and under normal circumstances, there is no way to perform joint spellcasting, and only by resonating the will to the same state, or frequency band, can they be jointly cast.

For a spellcaster like the elves who have reached a certain resonant state by perceiving the magic net and tempering their will, joint spellcasting is almost effortless.

However, for a caster like a human being, who directly compels the magic web, the personal characteristics in the will are extremely heavy, and it is relatively difficult to achieve a state of resonance between different casters.

But just as capital goes to great lengths to figure out how to make money, mentors also go to great lengths to figure out ways to exploit apprentices.

Synergistic Casting is almost every apprentice's first lesson after choosing a mentor!

But that's in the laboratory situation, where the mentor exploits the apprentice's work to the extreme, regardless of the state of the apprentice, usually only one or two apprentices.

In wartime, the situation is different, and it is necessary to coordinate the mental state of each person in the resonant state, although there will be a leader and a collaborator between the casters, but there is almost no excessive exploitation, and at the same time, there are more people and more difficult.

Xia Duo didn't do co-casting with anyone else in battle, at most he tried to co-cast spells with Nia in the lab to save energy, but it wasn't always very tacit.

This is true for both husband and wife, not to mention when there are many people, and they have to fight!

The battle is no better than anything else, the slightest mistake can not bring anything money to lose, but a small life may be lost.

Before, Xia Duo had always been curious about what kind of joint spell casting training Gilles Tower had summoned so many people, and whether it would be a gimmick more than practical!

Now it seems that he is too shallow in his knowledge and does not understand the essence of the Seven Towers.

In addition, the spells in the spell book should also be summarized after long-term practice, and are roughly divided into four types: protection, law breaking, movement, and restraint.

There are almost no lethal spells!

Perhaps that's why everyone is given a fireball wand.

……

The thought that there might be some kind of technology hidden in the spell book that could make the caster resonate effectively made Xia Duo's heart tickle like a cat, and even in the process of examining the differences in casting spells on the green plane, he thought about this question.

Several times, I almost made a mistake.

It's no wonder that Xia Duo is excited, but it is really the possibility of joint spell casting that means the existence of the mage legion, as well as the possibility of the existence of war spells.

In fact, on the projection plane [Mai Yerita Sukanvisa City], Xia Duo knew about the existence of the mage legion.

At that time, he took the form of an elf named Athos, a friend of Athos's deceased parents and the father of Athos's friend Grada, who was the head of the mages of Sukanvisa.

But it was in the Elven realm of the projection plane, and the main plane of Nessreal did not have a similar army of pure spellcasters.

Even the Great Xia Spellbreaker army envisioned by Xia Duo was supplemented by magic and killed the enemy with swords, rather than a pure spellcaster's army.

In addition to the fact that the caster is precious, has a high status, and is not easy to waste, it is also an important reason why large-scale combined spellcasting is difficult to achieve.

Even in the elven kingdoms of the main plane, Xia Duo has not heard of anyone who still retains a formed mage army.

Now seeing the joint spell casting auxiliary spell book that Nethrel took out, Xia Duo guessed that it was either specifically used to brighten muscles, or it was already known to the elves.

Otherwise, the accumulation is obviously more in line with the strategic expectations of the Nessera side.

Of course, it is difficult for Xia Duo to guess what the big names above think, but he knows that the Northland countries are likely to stage an unprecedented arms race.

So what does he have to gain in this arms race?

For a while, concepts such as mobility, population, spellcasters, and unrestricted warfare jumped into his mind one after another, stirring up a mess, and before he knew it, Xia Duo had stopped the inspection work at hand.

At this moment, Nia quietly leaned over and asked softly, "What's wrong?" ”

Xia Duo glanced at Belera and Vincent, who were still carefully casting spells to test the differences between the spells of different planes, and shook his head slightly, "It's nothing, continue to test!" ”

The two have been together for so long, and even the most intimate relationship has happened, Niya still knows Xia Duo well, and knows that the occasion is not right, so she doesn't continue to ask.

……

Soon after, Belera was the first to speak, "My test is over, except for the slightly stronger positive energy in the Green Plane Plane, the phase properties of other elements are roughly the same as those of the Main Plane. ”

This is a typical Arcanist-style simple conclusion.

As soon as Xia Duo and Nia heard it, they understood that the results were consistent with their tests, although it was only a side test, but it could also reflect the relatively real side of this plane.

It can be said that this secondary plane, named the Green Plane Plane, is more habitable than the main plane!