Cana carefully thought for a while before speaking cautiously.
"As Jellal just mentioned, all the cards in Calvin's deck are summon beasts of the Seven Stars, so I have no doubt that the remaining three enemies are also Seven Stars summon beasts."
"However, based on my knowledge, aside from these four Seven Stars cards, Calvin also has one called 'Demonic Summon,' which is also a Seven Stars card. As for the remaining two, I can't figure out what summon beasts they might be."
Jellal, upon hearing this, nodded in agreement. When he battled Calvin in the past, he had witnessed the power of the Demonic Summon. Although Calvin didn't unleash its full potential due to insufficient magical power at that time, there was no denying that the Demonic Summon was a formidable entity.
Suddenly, Ultear remembered something and asked loudly, "I once fought Calvin, and he summoned a seemingly weak and cute little dragon. However, after I used the Arc of Time to send it into the future, that little dragon instantly transformed into an extremely powerful giant dragon. I remember the summon beast's name was 'Millennial Dragon.' Could that be one of them?"
Cana, after a moment of contemplation, shook her head. "The possibility is low. The Millennial Dragon gains strength over time, and the span needed for it to reach its full potential is likely hundreds of years, if not more. Without your Arc of Time, it wouldn't have become a significant threat in just seven years."
"Then, what about Gia Friede?" Gajeel offered his opinion. "During my battle with Calvin, after I devoured his armor, Gia Friede suddenly became much stronger. It might be as formidable as the so-called Seven Stars summon beasts."
"And Calvin, that guy, in order to pass the S-Class promotion exam, he created many summon beasts tailored for the examinees. Those might also be a factor," he added.
Upon hearing this, Cana's eyes lit up, and she nodded repeatedly. "That's a possibility. Gia Friede was one of Calvin's earlier creations. At that time, to save magical power, he imposed certain limitations on it. However, in terms of strength, the Sword Saint Gia Friede is no less powerful than the Dragon Slayer."
Each person analyzed Calvin's summon cards, exchanging ideas and theories. However, despite gaining some additional speculations about the remaining summon beasts of the Seven Sins, they still couldn't confirm the identities.
At this point, Makarov, with a serious expression, intervened. "Continuing to speculate will only lead to guesses. Let's conclude this topic here. Regardless, now that we have confirmed that the enemies are Calvin's summon beasts, we must be mentally prepared."
"Old man is right. Let's discuss the plan for tomorrow's operation. Jellal, do you have any plans? It can't be just rushing in blindly, right?" Laxus, who had been quiet until now, also chimed in. However, for some reason, the others felt he seemed a bit impatient.
Jellal gave Laxus a brief look, then closed his eyes, organizing his thoughts before opening them again to speak.
"We do have a plan for the operation, but it's still in its infancy and needs further discussion."
"However, before we reveal the plan, there is some information that you all must be aware of."
Saying this, Jellal glanced at Ultear, who understood and took out a magical crystal from behind her, placing it on the table.
In the next moment, a screen of light emitted from the crystal, displaying various images.
"We've mentioned to Lord Makarov before that the Seven Sins have been collecting negative emotions from humans," Ultear calmly explained.
"The old man already told us about this, but I don't understand. How exactly do they collect negative emotions?" Laxus asked.
"I was just about to explain this, and it is also related to our operational plan."
With that, Ultear pointed to the black orbs, each about the size of a ping pong ball, displayed on the light screen.
"Although we don't know how they do it, these black orbs are the physical manifestations of the negative emotions they collect."
"They look like black glass balls," Mirajane commented.
Ultear glanced at Mirajane and continued, "Correct. At first glance, these orbs seem like ordinary glass balls. However, when touched, you can feel something peculiar about them."
"These orbs are referred to by the Seven Sins as 'Evil Spheres.'"
The light screen then flickered, revealing a strange and mysterious structure, resembling an altar.
The entire altar was constructed from dark minerals, decorated with depictions of demons with twin horns. In the central part of the altar floated a bone-made container, adorned with a painting of a demonic figure, terrifying and sinister.
The entire altar emitted a faint purple light, even visible through the light screen, giving off an unsettling atmosphere.
"After collecting these Evil Spheres, they transport them to a castle on Mount Olyx. Inside the castle, there are seven altars, each guarded personally by one of the Seven Sins. From this, we can deduce that these Evil Spheres hold significant importance to them."
"We believe that after absorbing the Evil Spheres, these altars generate an unknown force. This force is the true purpose behind the Seven Sins collecting negative emotions."
"Therefore, in our quest to defeat the Seven Sins, we must not only rescue Calvin but also destroy these Evil Altars."
"Infiltrating the castle, we need to split our forces and simultaneously destroy all the altars. Otherwise, if they sense that one of the altars is under attack, it might trigger unforeseen consequences."
Ultear finished her explanation, and everyone's faces turned serious. Facing an unknown enemy with unclear motives was a headache for anyone.
"Also, I think it's necessary to figure out why Calvin revived and whether it is related to these altars," Laxus added calmly.
"Otherwise, after destroying these altars, if Calvin dies again for no apparent reason, wouldn't our efforts be in vain?"
His words made many people realize the potential issue. The sudden resurrection of Calvin, who was supposed to be dead, had raised suspicions. Mavis, the founding guild master, had clearly stated that Calvin was truly dead and couldn't die again.
Cana's eyes flickered, and she had some speculations, but she wasn't sure if she should voice them.
What she was thinking about was Calvin's resurrection.
Another person with concerns was Jellal. He had completed the R system, and the colossal magical crystal in the Tower of Heaven had absorbed 2.7 billion concept magic. Under normal circumstances, that unstable magical crystal should have caused a catastrophic explosion.
However, he had never heard of any such incident happening. The Tower of Heaven had disappeared as if it had never existed. Since then, he had been suspicious that Calvin might be involved.
If Calvin was responsible, did he still have control over the R system?