Subsequently, the two stepped forward to demonstrate their techniques to Lu Chenxing.
Both of their techniques were learned from Super Martial University's Martial Arts Hall, following the traditional mage's path.
Xiao Guo was the first to cast a spell; she took out her staff and rapidly chanted a magic incantation.
"The Milky Way descends to the mortal world, thunder drums shake a thousand ravines!—Grand Waterfall Art!"
As she unleashed her spell, a massive blue magic circle instantly appeared above the dummy. The next moment, the surrounding Wind Element converged, transforming into a surging waterfall that crashed downwards!
Lu Chenxing observed this "Grand Waterfall Art" and found no issues with it. He had seen it in other people's combat videos; this technique was an unranked one, known by all water mages. Its power fluctuated with the user's strength: the stronger the user, the larger the summoned waterfall and the higher its initial drop point.
At Xiao Guo's current stage, having just entered the mid-second tier, the range, power, and drop height of her "Grand Waterfall Art" were already far superior to other water mages of the same tier.
The water quickly spread across the ground, and then a formation began to appear on the ground. All the water flowing on the ground immediately vanished, but it did not affect the spell above.
As the water column in mid-air descended, Xiao Lian, who was beside her, also began to cast her spell. Her black hair fluttered, purple light illuminated her eyes, and tiny purple lightning appeared around her body. At the same time, she chanted:
"Mighty heavenly power, thunder rumbles through the nine heavens! Yinghuo as the guide, Purple Extreme pierces the sky!—Heavenly Thunderfall!"
Subsequently, a purple lightning pillar struck straight down beside the waterfall. The sound of thunder and the roar of the waterfall brought immense pressure and power. The colossal sounds intertwined into a destructive symphony, even possessing some of the might of an enraged deity!
Lu Chenxing had also seen this technique before: the second-tier lightning spell "Heavenly Thunderfall." However, typically, lightning mages' lightning was light blue, dark blue, or white. The color of the lightning directly reflected the spell's power.
This purple lightning should be Xiao Lian's talent.
Lu Chenxing understood in his heart, and he also saw the problem with their two spells.
According to them, they originally intended to use the special reactions between elements to achieve certain effects, much like Lu Chenxing's three-element fusion spell.
Using Lu Chenxing's knowledge from his previous life, it was "water conducts electricity," which could achieve both control and armor-piercing effects simultaneously. Armor-piercing on the opponent meant increased damage for him, which was fine.
But now he found that when the lightning pillar struck down, the moment it entered the water, its power immediately plummeted. Its original power was also dispersed by the water flowing on the ground and finally absorbed by the ground!
Moreover, the strong impact, electric current, and high temperature brought by the lightning pillar, along with the high-density energy, even caused the waterfall's momentum to briefly pause. Although it quickly returned to normal, it indeed affected the spell's power.
"That's the situation, Boss Lu. Can you see anything?" Xiao Guo turned to him expectantly, and Xiao Lian did the same.
"Hmm, I have an idea," Lu Chenxing nodded slightly, then asked, "Xiao Guo, do you know any other magic, or just water-based spells?"
"Just water-based, because I am a Water Element specialist mage," Xiao Guo answered truthfully.
After receiving this information, Lu Chenxing felt a wisp of gas brought by the Wind Element. He roughly knew where the problem lay for these two.
"Xiao Guo, cast a Water Ball spell and hold it in your hand; no need to release it," Lu Chenxing performed his final verification.
Meanwhile, Xiao Lian on the side asked curiously, "What's wrong? Is there a problem with Xiao Guo's side?"
"It should be a talent influence. I'll know after I check," Lu Chenxing smiled.
Hearing this, Xiao Guo felt a little nervous. She was genuinely worried that she was holding them back. She tightened her grip on her staff slightly, then properly cast a "Water Ball spell."
Lu Chenxing felt this pure Water Element, and his guess was confirmed: it was a problem with the water.
The Water Element condensed by Xiao Guo, after being enhanced by her talent, had almost reached the level of "pure water"!
Water conducts electricity because it contains various impurities, such as various metal ions. These freely moving, charged particles are also called "charge carriers."
However, theoretically, pure water contains almost no charge carriers, so it conducts almost no electricity.
This is why when Xiao Guo's water magic and Xiao Lian's lightning magic were combined, they produced an effect where one plus one was less than one.
Only after Lu Chenxing explained this series of knowledge to them did the two understand. This was a type of knowledge they had never encountered before, but as high-achieving magic students, such minor knowledge was not difficult to comprehend.
"So, we can't cooperate anymore? We could still cooperate in the first tier," Xiao Guo looked a bit anxious, even a little disappointed. She was afraid she would lose Xiao Lian as a friend because of this!
At this moment, Xiao Lian smiled and embraced her, comforting her, "It must be because our talent effects are better now that we've reached the second tier! It's okay, even if we can't cooperate, we're still the best of friends, aren't we?"
"Oh, Xiao Lian~" Xiao Guo felt a warmth in her heart and choked up unconsciously, burying her head in Xiao Lian's embrace.
"Ahem!" Seeing the two of them looking rather intimate, Lu Chenxing quickly interrupted, "Don't rush, I haven't finished yet!"
Seeing that he still had something to say, the two quickly separated, behaving obediently like students being lectured by a teacher.
"Actually, it's very simple for you two to cooperate. Just find another Metal Element mage to cooperate with, or order a similar card from me. Anyway, artificially adding Metal Element will solve the problem," Lu Chenxing said.
Their eyes immediately lit up! They cheered with joy!
Seeing this, Lu Chenxing smiled and held up a finger, "There's one more thing I need to remind you about: the potential risks in your cooperation."
In his previous life, deionized water, or pure water, was most commonly used in electrolysis experiments. This meant that the combination of Xiao Guo and Xiao Lian's techniques could meet the conditions for water electrolysis experiments!
Just now, Lu Chenxing had discovered that when these two girls' spells combined, a large amount of hydrogen and oxygen was produced in the air!
The explosion limit for hydrogen is 4.0% to 75.6% (volume concentration), meaning that when the hydrogen concentration in the air is below 4% or above 75.6%, an explosion will not occur!
However, when purple lightning combined with pure water, the hydrogen concentration released at that instant definitely exceeded 75.6%, but at the same time, it was rapidly decreasing!
This meant that if they were in a confined space and used this spell combining Water Element and Lightning Element, the mixed gas of hydrogen and oxygen could very likely be ignited by Xiao Lian's Lightning Element, leading to an unexpected explosion!
Although hydrogen explosions are generally not too powerful, if it truly occurred in a very small space, the two would still be at risk of injury. Therefore, Lu Chenxing specifically informed them.