Under the hillside of the village, the fighters of the second platoon and the mage squad had trouble encircling the last stronghold of the enemy. There was actually a mid-level mage in this stronghold, a low-level mage and seven or eight archers were still resisting. The ice storm unleashed by the mid-level mage knocked the two squads that came forward to attack unable to advance an inch, and also caused a dozen or so fighters to suffer a lot of injuries.

The second platoon commander believed that a strong attack could pay a small price. Now it's time for the mage class to come out.

Outside the range of the opponent's magic and bows and arrows, the mage class is ready to cast spells.

Including Wu Qi, the nine mages in the mage class did not wear traditional magic robes, but wore the same camouflage uniforms as the surrounding guards, except that each of them wore a distinctive armband with a pattern composed of five stars, a magic staff, and two olive branches.

Most of these young men were time-travelers in the Guardian Guard, and their excellent magical talents allowed them to grow into low-level mages in a short period of time, and then selected from the army to become pure spellcasters who specialized in magic strikes.

The squad leader of the mage class stood in the middle, one person in each of the four directions of southeast, south, and northwest, while in the distance, the other four people stood in the four directions of southeast, southwest, northeast, and northwest, forming a square nested diamond-shaped formation around the squad leader, with an interval of more than one meter between each two people. And Wu Qi was standing in the southwest position, and since Huang Zheng was not there, they could only use the formation of nine people to release the combined fireball technique.

The technique of joint spellcasting naturally exists in this world, but it is often the work of several mages working together to perform large-scale magic. They cast spells at a distance from each other so that their magic does not interfere with each other, and when they are successful, they put together the various parts of the spell to produce an effect. It's like one magician is responsible for creating a large fireball, and another magician is responsible for pushing the fireball with the wind. The last mage is responsible for detonating it at a specific location.

But there has never been a practice of using multiple mages to release the same magic to increase the power of the output. Under normal circumstances, two mages casting spells together at close range often cause each other to interfere with each other, greatly reduce the effectiveness of the magic, or simply fail the magic.

As for Mao Kai of the magic group, when exploring the magic interference, he accidentally discovered that the magic interference of the same kind of magic may find opposite changes under different angles. Not only does it not weaken the magic effect, but it also increases the power of the magic in terms of power, time, or range. It has the effect that one plus one is greater than two.

He called this new discovery magical resonance. So he took the most common fireball technique as a sample and began to study the resonance of this magic.

He refers to two people casting spells together as two resonances, and three people together as three resonances. It took Mao Kai four hours to calculate the three resonances, and eight hours to calculate the four resonances, but it took three full days to reach the seven resonances. In the end, it took a whole month and a half to calculate the fireball technique to ten resonances.

According to calculations, ten resonants can already increase the explosive power of the fireball technique by 3 times, increase the range by 1.7 times, and increase the magic piercing effect by 0.8 times. You know, this is a 3-fold increase in the destructive power of the ten fireball spells themselves. It's a leap from a knife to a giant axe. In this case, the low-level magic of joint spellcasting is even more powerful than many high-level magic.

However, the hard work of more than a month was not in vain, Mao Kai and a research team composed of seven or eight teachers and students from mathematics, physics and computer science majors summed up a set of algorithms in the process of calculation. With this algorithm, most magic can automatically calculate ten resonances as long as it counts six resonances.

Although the calculated result is not the final version, and it will have to go through various adjustments and changes in the future, it greatly reduces the time to calculate the resonance position.

Of course, the more complex the magic, the more time it takes, and a basic magic like the Fireball Technique will take a month and a half, and if it is a complex magic like the Heart of Fear, it may not be able to count the ten resonances in a few years. And those two resonances have to calculate a week's worth of high-level magic, and it is simply unrealistic to rely on manpower to develop ten resonances. But with the help of this algorithm, with the help of computer software, it is really feasible.

Mao Kai's discovery aroused great interest among the escorts. Wang Jiyuan, who was full of the concept of modern warfare, had long wanted to put magicians into the contract combat system. Magical Resonance inadvertently opened the door to co-casting as a basic way of fighting for army mages.

However, although there is theoretical support, as the caster itself, it is necessary to cooperate closely and synchronize the movements when casting the spell, which requires a lot of training to achieve. Therefore, although Mao Kai they have developed ten resonances of seven or eight spells. But it took Wu Qi and the others a month to practice the fireball technique to 80% synchronization rate, and the sleep technique to 50% synchronization rate.

And today, for the first time, they have actually put this tactic on the battlefield.

"Fireball, Preparation, Three, Two, One, Chanting. Following the squad leader's command, the nine began to chant the mantra together.

The so-called magic spells do not serve any purpose in themselves, they are just formulas to help the mage sketch out the model. In essence, it is the same thing as the mantra (note) of the old man. Therefore, different magic towers are likely to have different formulas for the same magic, and each mage will adapt the mantra according to their own needs. For those who are very proficient mages, there is naturally no need to chant mantras.

But spells are very useful in co-casting. By following the spell, it will be easier for all mages to synchronize their rhythms, and the effect of spell casting will be much better.

While the fireball technique was still being prepared, there was a trace of magic swimming between these mages, making them seem to be in a red light gauze tent.

When the last spell in the mage's mouth ended, nine fireballs flew out of their hands together, and under the traction of the surrounding forces, they merged together to form a super fireball. Like a meteor, the fireball pulled out a bright arc in the air, spanned a distance of nearly two hundred meters, and landed on the enemy's stronghold.

With a loud bang, the fire was full of flames and smoke and dust billowed up. The enemy's stronghold and the people inside were blown to the ground by a fireball, and even the mid-level mage was shattered by the shattering of the shield and burned to charcoal. Only the most powerful warrior stumbled out of the flames, his body scorched black, his body still bubbling with flames, and he didn't take a few steps before he collapsed with a bang, and he was silent.