This was a combined formation devised by Yang Hong, incorporating the law of conservation of mass from Blue Star and generator theory. It not only solved the problem of weak formation defense but also incidentally increased the spiritual energy of Yuliu Island.
The theory was quite simple: use defensive formations to withstand attacks, then transform this energy into spiritual energy through the formations. The difficulty lay in the combination of these formations.
For the more than half a year after Yu Kewei's departure, Yang Hong had been focused on one thing: perfecting his "Conservation of Energy Formation Combination." It seemed to be effective now.
On the sea, twelve demon races dispersed, launching various spells at the space above the water. Although these attacks were neutralized by the defensive formations, they left traces. With these traces, the demon kings could pinpoint the exact location of Yuliu Island. Furthermore, such attacks could also help identify weak points in the formations. If one of these attacks managed to break through, it would save a lot of trouble.
However, what Lei Hu and the other demon kings did not expect was that after a day and a night of attacking, apart from delineating the formation's perimeter, there were no other surprises.
"Everyone, return to the ships and recover your magic power. Let our subordinates do some work too," Lei Hu, feeling about seventy percent of his magic power depleted, called out to his brothers who were still attacking fiercely.
"Boss, I can still go on. I want to keep attacking," the rat-faced man shouted unwillingly, his spells still bombarding the space before him.
"Shu Kaihuang, don't overexert yourself. Recover your magic power first. If there are other dangers after the formation is broken, you'll be dead," Lei Hu said with disdain, glaring at the rat-faced man before transmitting his voice to other demon kings further away.
"Boss, this formation on Yuliu Island is quite interesting. We might be in for a prolonged battle," the sheep-faced man, who returned last, said with a smile. Despite mentioning a prolonged battle, there was no trace of worry on his face.
"Brother Yang Cong, have you discovered something? Tell us about it," Lei Hu asked curiously, sensing the tone of Yang Cong, the sheep-faced demon king.
"Heh heh~ Through my observations, I can confirm that the formation on Yuliu Island is not being controlled by anyone. Otherwise, after we've been attacking for so long, the owner inside should have come out to organize a defense. Even if King Lei Peng is not here, that sycophant should have shown up, but not even a fourth-tier demon has appeared so far. What does this imply?" Yang Cong paused here, looking at the other demon kings with an unfathomable expression.
"Does it mean there are no demons on the island?" the rat-faced demon king, Shu Kaihuang, asked cautiously, not entirely convinced himself.
"Heh heh, Shu Kaihuang is being smart for once." Yang Cong stroked his inch-long goatee and praised Shu Kaihuang with a smile.
"But... but is that possible? What about the demons on the island? We all know that Yuliu Island has over 3,000 fourth-tier demons, more than 600 fifth-tier Great Demons, and two sixth-tier Demon Kings. Where could so many demons have gone?" Hearing Yang Cong's affirmation, Shu Kaihuang negated his own guess.
"Who knows? Maybe the Golden Peng Ancestor got hungry and swallowed them all in one go." Yang Cong's casual remark, without realizing it, uttered an answer that was close to the truth.
"Heh heh~ How could that be? Although the Golden Peng Ancestor has a large appetite, he wouldn't eat his own grandson's subordinates, would he?" Shu Kaihuang didn't believe it, shaking his head vigorously.
"Alright, everyone, recover your magic power first. I believe we'll know the truth soon enough," Lei Hu said thoughtfully, glancing at Yang Cong before proactively changing the subject. He then turned and shouted towards the deck of the sea ship.
"Fifth-tier Great Demons, go up and attack. All of you, use long-range magic attacks."
Immediately, 180 fifth-tier Great Demons flew off the sea ship, quickly dispersing and beginning to attack Yuliu Island.
Yang Hong scoffed dismissively as he watched these fifth-tier Great Demons. Sixth-tier Demon Kings couldn't shake his defensive formation, so these fifth-tier demons were just giving him freebies.
"Perfect, I'll use this opportunity to adjust the formation." While the fifth-tier demons were attacking Yuliu Island, Yang Hong extended his divine sense, observing the entire Yuliu Island and making adjustments to the existing formations. He dismantled some formations that were of little use or didn't contribute much to defense and rearranged them into defensive formations and energy conversion formations.
The result was that as the demon attacks continued, the outline of Yuliu Island gradually became visible.
"King Lei Hu, Yuliu Island has appeared."
"Hahaha~ It's appeared, it really has appeared."
"Brothers, keep up the effort and break this defensive formation."
Seeing Yuliu Island appear, the fifth-tier Great Demons became excited. This was Yuliu Island that the sixth-tier Demon Kings had attacked for a whole day without success! They, the fifth-tier Great Demons, had made it appear in just half a day. This was an achievement!
Lei Hu, who was recuperating, looked at the island on the sea and then at the ripples in the air. He wasn't particularly happy. He could see that the defensive power of the formation had not diminished much.
"It's appeared, so what? Why are you so excited? Break the defensive formation first, then celebrate." He berated the fifth-tier Great Demons and continued to recuperate.
The other demon kings understood the situation after hearing Lei Hu's words. They would only join the attack again after their magic power had recovered, allowing the fifth-tier Great Demons to rest and recover.
After a continuous month of attacks, Yang Hong, using the spiritual energy converted from the demon attacks, upgraded the core array eyes of all 12,960 defensive formations to fifth-grade spiritual plants.
"Big Brother, should we keep attacking? This island's formation is probably a seventh-grade formation." After a month of attacks, Yang Cong began to doubt his judgment.
"Perhaps we should withdraw. This Yuliu Island is truly strange." Lei Hu had also lost confidence. He now suspected that someone was controlling the formation on the island.
"Boss Lei Hu, retreating now would be a bit of a waste, wouldn't it? How about we concentrate on one spot and try to break through?" Shu Kaihuang was already panting, but he didn't want to give up. He had spent over ten thousand spirit stones this month and wanted to recoup some of his losses.
"..." Lei Hu frowned and pondered the suggestion.
"Boss, we can try." Yang Cong was also unwilling to give up and then proposed.
"Alright~ Everyone gather, listen to my command, and concentrate your power for a single blow at this target in front of me." After considering it, Lei Hu agreed.
192 demons quickly gathered.
Yang Hong also noticed the demons gathering and immediately guessed their intentions. "They want to combine their strength for a single strike? Heh heh~ I'll let them in, and then..." Yang Hong began to rapidly adjust the formation.
"Three, two, one, attack!"
"Boom~"
192 attacks landed sequentially on a single point in the void. The void trembled, and a passage paved with white light instantly opened.
"Quick! Charge in!" Seeing the white light passage, Lei Hu didn't hesitate and rushed in first. The other demons followed without suspicion. After they entered the passage, the white light passage instantly closed.
"Charge! Charge!" The demons shouted as they entered Yuliu Island, immediately sensing the spiritual energy that was much denser than outside. Everywhere they looked, there were spiritual plants and herbs. The demons no longer cared about who was the boss and scattered to grab the spiritual plants.
However, as soon as they landed, they were trapped by various trapping formations.
"Heh heh~ Welcome to my territory, my lambs." When the demons realized something was wrong, a slightly impertinent voice echoed in their ears.