As it turns out, unhindered by space, Casey was actually able to cast skills much more powerful than Sero had expected. The boy's voice cracked, but a bright flash of yellow light lit up the clearing, followed by a blast of cold air that sent leaves swirling through the air as he casted Ice Shard. Sero felt a shiver run down his spine as he realized just how powerful Casey's magic was. He glanced over at Nala, who looked subtly pleased with the boy's progress.

"Very good, Casey," she said, her voice calm and encouraging. "You've made great strides since our last training session. Now, let's work on controlling your magic a bit more. Remember, precision is key. Focus on making your spells more focused and controlled."

"Last training session?" Sero glanced at Nala. "I thought the last one was in my penthouse."

"Oh, we trained a bit more while you were recovering at the association infirmary," Nala replied. "At... your penthouse."

"Wait, what? Did you guys break anything–"

A thundering flash of yellow lightning crashed down, interrupting Sero as Casey casted Lightning Bolt. The air crackled with energy as another bolt of electricity shot forth from the boy's outstretched hand, hitting a nearby tree with enough force to make it splinter. Even from several feet away, Sero felt the hairs on his arms stand on end from the power emanating off the spell. He couldn't help but grin with admiration.

"Damn, Casey," Sero remarked, impressed. "You really have been working on your control. That was pretty good." He glanced at Nala, who nodded in agreement, a visibly proud smile on her face.

"All right, let's try something a bit more advanced," Nala said, stepping forward. "Remember how you've been trying to cast Earth Spike efficiently?"

Casey nodded, his expression determined. "I've been working on it," he replied, "but it's still kinda hard to control. I'm scared of messing up this place."

"It's ok, we're in a personal space now," Nala assured the boy. "Even if Sero himself were to unleash everything he had, it wouldn't really do much, so go wild."

Sero snorted. "Is that a challenge?" he muttered under his breath as he watched Casey cast Earth Spike.

The boy closed his eyes and concentrated, his hands shaking with effort. Slowly, a small, jagged spike of earth began to form in front of his outstretched palm. It grew larger and larger, stretching upwards until it was several feet tall, its tip pointed at the sky. Casey opened his eyes, a triumphant grin spreading across his face. Sero's body buzzed as he copied the skill.

Earth Spike was a simple skill that literally conjured pillars of earth from the ground. They were stationary, but useful in tight situations, able to shift its height quickly according to the caster’s will.

"Very good," Nala said, her voice tinged with a hint of pride. "Now, let's see if you can control it enough to use it defensively."

"If I'm not the one training him, then what the hell am I here for?" Sero grumbled as he watched Nala throw exploding mana knives at Casey to test his defensive capabilities of Earth Spike. The boy skillfully dodged each knife, using his Earth Spikes to deflect them harmlessly away as they detonated with a violet light. Sero was surprised that a boy as young as Casey was able to handle the situation so well.

"Mr. Sero, you should throw some knives, too!" Casey shouted to him, a slight arrogance creeping into his voice. "I bet I can defend from both you and Miss Nala!"

"Are you sure?" Sero asked, but nevertheless threw mana knives at the boy. Immediately, Casey was unable to handle attacks coming from all sides, failing to block the explosion from one of the knives and getting launched backwards into a tree.

The boy wheezed as the air was knocked from him, falling face-first onto the ground. Sero fought back a laugh as he quickly rushed to his side, casting Recovery. Out of the corner of his eye, he saw Nala struggling to stop a smile from blooming across her face, giving Sero a false look of disapproval.

"Are you... okay, kid?" Sero had to bite his lip.

"I'm fine, Mr. Sero," Casey grunted as he sat up, apparently unfazed.

Nala walked over to them, her expression serious. "You did well for a beginner," she told him, "but you need to learn to keep your focus when things get hectic. Sero was just testing your limits."

Casey nodded, his expression thoughtful. "Yeah... I guess I did get a little confident there," he muttered, rubbing the back of his head.

As they continued to practice, more carefully this time, Sero couldn't help but feel a sense of pride in the boy's progress. Even though Casey was still much younger and less experienced than he was, there was something about the boy's determination and raw talent that reminded Sero of himself.

Pretty soon, both Nala and Sero could tell Casey was growing exhausted, so they decided to wrap up training. The boy's eyes were heavy with sleep, and his movements were becoming more sluggish. Even so, he still managed to surprise them with a particularly impressive display of Earth Spike control. As he spun around, his arms outstretched, a spike formed beneath each foot, allowing him to spin faster and faster, like a spinning top. The display was dizzying and awe-inspiring.

This tale has been unlawfully obtained from Royal Road. If you discover it on Amazon, kindly report it.

"What do you... plan to do by doing that?" Sero called out to him.

Casey's face lit up with excitement. "I was thinking of using it to defend myself in the arena!" he exclaimed. "Like a spinning tornado of earth!"

"But... you're just spinning in place. There's nothing around you to help you defend."

"Oh," Casey's voice sounded distorted as he kept spinning. "What if I could make the earth spin with me? Like a giant shield?"

"Yeah, that'd be great!" Sero yelled back. "How 'bout you try it right now?"

Casey closed his eyes, concentrating. The ground beneath him rumbled softly as the earth itself seemed to respond to his will. With each rotation, the movement became more pronounced, the earth rippling outwards like water in a pond. Soon, a miniature version of the tornado of earth formed around the boy, spinning at an incredible speed. It was clear that he had managed to control the earth itself, using it as a shield.

With a jolt as his body buzzed with power, Sero realized that Casey had developed a new skill 'Ground Fortress'. By using the base concept of Earth Spike's static positioning, Ground Fortress enabled the user to move the earth more freely using their will.

"What the... did Casey just make a skill?"

"Yeah, he did," Nala glanced at Sero curiously. "Did you not know that that's how advanced classes of the Mage develop skills? Every Mage learns the basic elements and creates new skills from those. My Shadereaper skills are based off of the darkness element."

"Wait, that's broken."

"As broken as you being able to copy any skill? You realize you’ve already created new skills like that one Starfall Nuke, right? Not to mention you can copy passives too."

"Oh yeah," Sero grinned sheepishly. "Good point."

Casey abruptly stopped spinning, tumbling to the ground as he began to vomit from the prolonged skill usage. Sero looked at him with a mixture of concern and surprise. Casey was reminding him more and more of like when Sero first returned to Earth.

----------------------------------------

In the late afternoon, the three of them were brought back to Sero's penthouse, exhausted and hungry. They found Luna munching away on fried chicken as she greeted them with a burp.

"Well, well, well," she said between bites. "Look who's back. Did you have fun?"

Casey nodded, wiping the sweat from his brow. "It was intense, but yeah. I think I got better." He glanced over at Sero, a hint of uncertainty in his eyes. "Thanks for training me, Mr. Sero. And Miss Nala."

Sero grinned at the boy. "No problem, Casey. You've got a lot of potential. Just keep working at it." He glanced back at the succubus. "I hope you ordered enough for all of us."

"I... y-yeah I did," Luna stammered, her face flushing as she glanced between Sero and Nala. It was clear that she hadn't been expecting them to come back so soon. "Um... there's a lot of food here, so you guys can have as much as you want."

Sero could tell Luna had expected to eat all of the food herself as he smirked and sat on the couches, watching the others gather around the table. He snapped his fingers, conjuring Moss and Lime to add to the lively atmosphere; the lighter dragon pup immediately made a beeline towards Casey and assaulted the boy.

The tv played quietly in the background as the four ate and talked. Sero couldn't help but feel a sense of contentment as he watched his friends and the young prodigy enjoy the meal.

"Miss Luna, does beer really taste that good?" Casey asked, struggling to keep Lime at bay as the succubus popped open another can.

"Yeah, wanna try it?" Luna smirked, offering the can to the boy.

"Hey, whoa now," Nala said, reaching out to take the beer from the succubus. "You're only ten, remember? You're not even supposed to be drinking that stuff."

"Aw, come on," Casey protested, trying to grasp at it while holding Lime away with his other hand. "I just want to know what it tastes like."

"Sorry Casey, but Nala's right," Sero chimed in, giving the boy a pat on the shoulder. "Drinking's not something you should be getting into yet. You've still got a long way to go before you're old enough to be enjoying things like that."

"But I'm not a little kid anymore," Casey insisted. "I'm stronger and faster than most people. I can take care of myself. Why can't I have a sip of beer?"

"I just watched you throw up after spinning for too long, so I'm pretty sure you're still a kid," Sero pointed out with a teasing grin. "And besides, there's plenty of other stuff you can enjoy being a kid. Like, uh, going to the movies, or playing video games, or..." He trailed off, glancing at Nala for help.

"Don't look at me," the Shadereaper replied. "I didn't have a lot of friends growing up."

"Neither did I," Sero admitted with a shrug. "But that's not the point. The point is that you should enjoy being a kid while you can. You'll have plenty of time to grow up and do adult stuff later."

"How do I learn how to do that? My parents aren't around, and my grandmother is gone, too."

The three adults fell silent, glancing at each other after hearing Casey's words. Sero shifted uncomfortably before he spoke, "Well, you know, life's not always easy, kid. But you've got friends now, and a place to stay. That's the most important thing. Just focus on being happy and enjoying yourself." His heart ached, realizing that Casey was now in the same position as him.

Luna cleared her throat, trying to lighten the mood. "Hey, let's not get too serious here. We're supposed to be enjoying ourselves, right?" She winked at Casey. "Maybe we could take you to the movies sometime, if you'd like? Or how about a trip to the arcade?"

"Okay!" Casey exclaimed, his expression lighting up. "I'd like that! Going to the movies and the arcade would be a blast." He paused, then looked at Sero with a serious expression. "Thanks, Mr. Sero. And thank you, Miss Luna, Miss Nala. I mean it. You guys are the best friends anyone could ever ask for."

Sero lowered his gaze, feeling a pang of sympathy for the boy. "You're welcome, Casey. We're just glad to have you as part of our little family now." He paused, then added with a grin, "And you can call me Sero, you know. 'Mr. Sero' makes me feel old."

"Uh, okay, then," the boy hesitated for a moment. "Sero."

Casey and Sero immediately cringed.

"Yeah, that didn't feel right," Sero said with a laugh. "So, Mr. Sero it is, then."