Dante flipped open a fresh page and titled it 'Chainstride.' "Alright, Little Rabbit. Tell me, what do you know about your quirk?"
Rinji spoke softly. "I… I can move faster. If I keep moving, it gets faster and faster, but I don't know how much or why."
Dante tapped his pen on the paper, thoughtful. "Alright, we can spend today figuring it out."
He stood and pointed to a bulky, non motorised, curved treadmill, an Air Runner. "Step on. This thing moves when you move. I'll be checking the speed counter above. Run as fast as you can."
Rinji obeyed immediately. He climbed on, a little clumsy at first and tried to run—only to stumble and fall off with a soft thud. Dante didn't say anything. Rinji got back up and tried again before Dante could help. This time, he managed to find his rhythm.
Dante watched closely. He glanced at the speed counter and began writing.
8 MPH base speed, great for a kid.
8.8 MPH
9.7 MPH
10.6 MPH
12.2 MPH
It's a +10% increase?
How often does this occur? Each step?!
His eyes narrowed. "Not stamina-based… not time-based…" he muttered. "It's the step. Each individual step is a multiplier. Exponential scaling…"
12.2 MPH
13.4 MPH
14.7 MPH
16.1 MPH
17.7 MPH
19.65 MPH
When Rinji hit 20.75 MPH, ten steps in, something changed. The blue and purple markings along his arms, legs and cheeks started to emit a faint glow. Barely noticeable. Like bioluminescence beneath his skin.
Dante didn't miss it.
At 10 steps : faint bodily glow, an indicator? Could this be the limit?
Still, Rinji kept going. And he kept getting faster and faster.
22.83 MPH
25.11 MPH
27.62 MPH
Dante's eyes squinted as he tracked him carefully. The treadmill perfectly fine, designed to withstand high speeds.
But one thing Dante had forgotten, the faster he moved, the faster the steps would come, leading to an even greater acceleration.
Then. At around 25 steps, something else changed.
The glow intensified, vivid and sharp now. Rinji's body lit with radiant streaks of blue and purple, the marks glowing brighter than before. His heterochromic eyes one purple, one blue, started to burn with the same colours.
Dante's pen scribbled to keep up.
At 25 steps : vivid glow in body and eyes.
No sign of exhaustion.
No deceleration, only gain.
Rinji didn't stop. His limbs started to blur. The sound of each footstep was a crack, not a pat.
Range stood up. "Little Rabbit."
No response.
95.35 MPH
104.89 MPH
115.38 MPH
Dante stepped forward.
"Rinji, stop. You're doing too much."
Still no response, his mind seemingly overtaken by the movement. The momentum.
Then came the 50th step.
A sonic shockwave echoed through the room, shaking the walls and nearly knocking Dante over. "M-Mach 1?!"
Dante moved.
He bolted forward, intercepting the child mid-step and pulling him off the runner.
Rinji gasped, like he was waking from a trance, collapsing into Dante's arms, panting. His limbs still twitched and cracked with energy. His glowing skin slowly dimmed, the electricity dissipated.
Dante crouched, setting Rinji gently on the mat and kneeling beside him. "You good?"
Rinji nodded. "…I'm good…"
Dante reached for his notebook again.
At 50 steps, around 939.12 MPH, which is about a 11,639% increase from 8 MPH : Violent glow, bright blue and purple electricity starts to eminate.
Still no burn out, somehow. Body accelerates until forcibly stopped.
Needs external limiter or training to limit, maybe the indicator can be used as a gear shifting mechanism through training.
Backlash : Motion induced intoxication. He seems to be high or drunk, his limbs are also twitching uncontrollably.
He closed the notebook with a snap and looked at Rinji.
"You can stay here forever, so long as you allow me to train you. Your quirk's potential seems to be… infinite."
Rinji looked up at him, his eyes unfocused and he was shaking slightly.
"I-I'm sorry… I didn't mean to—"
Dante put a hand on his head. "Don't apologise. You did great. But we've got to learn to control it before it controls you."
Rinji's eyes slowly regained focus as he nodded. "Yes, sir."
Dante then crouched infront of him, holding out a bottle of water.
"Drink," he ordered, voice firm.
Rinji blinked slowly as he took the bottle and gulped it down like a dehydrated puppy. After a few seconds, he swayed, hiccuped and gave another nod.
"That's the downside of using your quirk," Dante muttered. "Mental disorientation. Maybe due to oxygen burn or neurological overload from processing your movement too fast."
He glanced up. "How are you feeling?"
Rinji smiled dreamily. "…Like I'm on a cloud…"
"Yeah, no more clouds. Stay on the ground." Dante said, standing up and lightly ruffling the boy's hair. "Sit still. Let the water settle you."
About twenty minutes later, Rinji was somewhat back to normal.
"Okay," Dante said, "let me break this down for you."
He tapped the page and grinned slightly. "You ran at a speed of 939.12 Miles Per Hour."
Rinji tilted his head, confused. "Is that fast?"
Dante nodded. "Faster than sound."
The boy just blinked.
"You know thunder?" Dante explained. "It comes after lightning because light moves faster than sound, right? You just ran faster than thunder could catch up to you. If you ran past someone, they'd hear you coming after you'd already gone."
Rinji's mouth fell open a little. "…Really?"
"Yeah," dange said, leaning back with a smirk. "And I had to catch you before you flew through the roof and ended up in another country."
Rinji didn't reply.
"Alright, you ran like a bullet," Dante said, standing up and stretching his arms. "Now let's see if you hit like one."
Rinji blinked. "I don't think I'm very strong…"
"We'll find out," Dante replied simply, already moving toward the weight bench in the corner of the room. It wasn't fancy, just steel plates, a pull up bar and a punching bag wrapped in torn up tire rubber, it was good enough.
Dante motioned for Rinji to stand infront of a training dummy.
"Punch it."
Rinji hesitated, then balled his small fists, stepping up to the dummy.
He glanced at Dante, who gave a silent nod of encouragement.
The boy's knuckles tapped the dummy with a quiet thump. Barely anything.
"Again." Dante said.
Rinji did, slightly harder.
"Harder."
Another hit. A bit more force, still soft though.
Dante's expression didn't change. "Come on, harder, Rinji."
Rinji's fists clenched, nervous. His eyes flicked up to Dante again and this time, the fear of disappointing him pushed through his hesitation.
He stepped in and punched with everything he had.
*THUD!*
The dummy shifted a few inches back.
Dante nodded slowly and wrote something down in his notebook.
Strength : Normall for an 8 year old. Approximately 60-70 LBS of striking force. His quirk doesn't seem to affect strength.
"Not bad," Dante said finally, as Rinji stood there, slightly rubbing his hand. "You're not weak. You're just more speed focused than strength."
Rinji nodded shyly, seeming relieved.
"Next up," Dante said, standing and tossing him a ball. "Reflexes. You should be good at this."
Rinji caught it without looking.
Dante's eyebrow lifted. "See."
He turned and walked over to a flat wall with faint scruff marks on the wall, then pulled a drawer from the wall and took out a handful of small red balls.
"These are pressure softened. They won't hurt you. Now stand against that wall and dodge."
Rinji obeyed.
Dante stood about fifteen feet away. "You're not allowed to move your feet, just your upper body."
He threw the first one. Rinji tilted his head and it whooshed by.
Another. Rinji ducked, not blinking.
Third, he twisted sideways, his eyes starting to glow faintly.
Dante increased his speed, throwing two at once. Rinji's hands flicked up and smacked one aside while the other flew past his shoulder.
His body was moving fluidly, like he could already see where the balls we're going. Like time was moving slower for him, all while the marks on his body were slightly glowing more and more.
Dante's eyes narrowed.
'Are his reflexes getting better?'
He threw four more. Rinji dodged all four of them, bending his body at sharp angles to dodge all of them perfectly.
Dante threw five.
Rinji caught two, his markings glowing violently now.
Dante stared for a second, then smiled.
"Don't forget to blink." He said.
Rinji suddenly blinked, and the marks on his body stopped glowing.
Dante threw five again.
Rinji only managed to catch one and dodge one, the other three hitting him.
"Alright, that's enough." Dante said, walking over and patting the boy's shoulder. "Your reaction speed is incredible. Maybe even better than mine if you hold your eyes open long enough."
Rinji was flushed, breathing hard and slightly tipsy, but excited nonetheless. "D-Did I do good?"
"You did better than good," Dante replied, grinning proudly. "It seems your quirk affects more than just your running speed. Holding your eyes open increases your reaction speed and overall perception."
Rinji stared, wide eyed.
"See now that leads me to believe something else…" Dante said ominously, scribbling one more note before he started walking back toward the training dummy. "Force = Mass x Acceleration, right?"