Mana core
With the use of Miles's evolved ice magic, the gorilla began to freeze and was completely encased in ice. However, since the simulation had not ended, it wasn't truly dead. Miles still had tricks left up his sleeve. Silently, so Raven behind the glass couldn’t hear, he said, "Ice Coffin." This technique was a deadly spell that only Everfrost users could execute. The strength of ordinary ice was not sufficient to perform this technique. Additionally, a normal ice user would expend far more mana trying to encase such a large giant in ice than an Everfrost user would.
The layer of ice surrounding the gorilla began to freeze the inside as well. All the gorilla's parts crushed inward and turned completely to ice. When the simulation ended, the ice statue remained in place. Raven did not initiate chapter 6 because Miles had previously explained the power difference between chapters 5 and 6. Even with the Everfrost ability, chapter 6 would be nearly impossible.
Miles signaled Raven to open the door. Raven opened it, and when Miles stepped out, they shook hands. Miles said, "Technically, we’re both ready. From now on, you’ll work on your physical abilities, and I’ll work on my mana capacity. We need to do our best in this week." Raven nodded in agreement and pressed the buttons to shut down the system. Then they began walking home, the sound of their echoing footsteps being the only thing heard.
As they walked, Miles started to talk: "How about naming your technique 'Ultra Instinct'? After all, you're fighting using your instincts." Since Raven wasn’t particularly interested in such things, he accepted his brother’s suggestion. Miles had an idea. Knowing their development would be limited during the week, he suggested getting a professional training program. Raven was open to the idea as well, since a week was quite limited.
When they returned to the mansion, they entered Trainer Rufus’s room. Miles didn’t explain why they needed strength because if it reached their father’s ears, there was a high chance of civil war breaking out. He simply stated that they needed to become as strong as possible and requested the toughest program. Rufus hesitated, but seeing the desperation in Miles’s eyes, he decided to provide the program. Since it was the first time in his life that Miles had asked for a special program, Rufus couldn't refuse him. "Sit down," he said. The kids looked at each other and sat down. Rufus pulled back the cover hanging on the wall behind him. Behind the wall was a chalkboard. Rufus took a piece of chalk from his desk and drew a stick figure.
"This is you, Miles," he said, drawing a round mana core in the stomach area of the stick figure. "This is your mana core. It's a spiritual piece, but it can be physically destroyed." He drew a larger circle and divided it with lines. "You can think of these lines as your mana core that you expend every time you use mana. So, think of mana like firewood that you burn. Your affinity determines the result of the spell. Since you have an affinity for every spell, it doesn’t matter what your fire or match is."
Rufus continued by drawing a pile of firewood on the board: "What generates mana is your mind. The stronger your mind, the more mana you can store. You can grow your mana core. Let’s say you can bring five pieces of firewood every day for the first month, but because your body strengthens in the second month, you might be able to bring six or seven pieces every day. Your mind produces more mana every time you use mana."
Miles grimaced, "But what does that have to do with rapid development?" Rufus grinned: "Your limit is five pieces. If you expend five pieces, you can use six pieces the next month. But if your limit is five and you expend ten pieces, you can use eight pieces next month."
Miles found it even more ridiculous: "But how can I accumulate and expend ten pieces when my limit is five?"
Rufus excitedly replied, "You can’t do that unless you don’t burn down your house made of firewood! You’ll have to use your mana core as well. Your recovery will take at least three days, but by the seventh day, you could double or even triple your mana capacity," he said. Though Miles felt tense, he nodded, knowing he had no other choice.
Rufus wiped the board and turned to Raven, beginning to speak: "And as for you, Raven..."