Every morning, as the damp mist of the Land of Steam still clung to the jagged rocks of the border, Gorilla would sit in a meditative stance, his face tight with concentration.
His primary task was simple but grueling: fill the Cross Seal on the back of his hand to its absolute bursting point with chakra.
Once his natural stamina and chakra reserves had recovered from the initial drain, he would perform a single, sharp hand seal. In an instant, he would extract the entirety of the stored energy.
The sensation was akin to a dam bursting within his tenketsu. Pure, raw chakra flooded his system, stimulating his muscle fibers and reinforcing his skeletal structure until they hummed with kinetic potential.
Every cell in his body screamed under the sudden influx, and the air around him swirled into a localized gale, kicking up dust and loose pebbles.
Gorilla didn't release the energy immediately. His natural chakra capacity was intrinsically linked to his physical constitution; under normal circumstances, he simply didn't have the "vessel" to hold this much power.
But then, he triggered the second phase of the Cross Seal.
The reservoir opened. The massive surge of chakra that he had previously stored—energy that was fundamentally his own—poured back into his pathways.
Because the chakra bore his own signature, his body didn't reject it with the violent immunological response it would show toward a foreign energy source. Yet, the sheer volume was unnatural. It was like forcing a torrential river through a narrow irrigation pipe.
The pressure stimulated Gorilla's muscles, bone marrow, and internal organs with a brutal, electrifying intensity. He would hold this state, sweat pouring down his mask, his body trembling with the effort of containing the "overload." Only when his vision began to blur would he weave the signs to vent the energy.
"Earth Style: Earth Flow Thorn Forest!"
A massive thicket of jagged stone spears erupted from the earth, covering a radius of nearly thirty meters. The spears were thick, interlocking, and reached several meters in height—a devastating area-of-effect technique that was far beyond the typical output of a Special Jonin.
Yagami, watching from the sidelines with his arms crossed, nodded in approval. "Not bad. That Earth Flow Spear finally has about thirty percent of my own flair."
Gorilla collapsed, gasping for air as the stone forest settled. It took him nearly half an hour just to recover from the sheer fatigue of such a massive expenditure.
This was the "Limit Stimulation Training" Yagami had designed: repeat the process three times a day. Yagami stood by with a notebook, recording every fluctuation in Gorilla's chakra and physical state.
He was navigating uncharted waters; he didn't know if this would truly break the genetic ceiling or simply shatter the subject. He lacked the cold, clinical detachment of Orochimaru, who would have likely pushed the stimulation until Gorilla's heart exploded just to find the "red line." Yagami had to be the scientist and the comrade simultaneously—a difficult balance.
For fifteen days, the rest of the division handled the border patrols while Gorilla was granted special leave to train under Yagami's direct supervision. On the sixteenth morning, Gorilla stood up, his eyes bright with a fervor Yagami hadn't seen in months.
"Captain! My body... it feels different! It's stronger! My natural chakra pool has actually started to grow again!"
Yagami had him demonstrate. Without tapping into the Cross Seal, Gorilla's standard Earth Style techniques were visibly larger and more refined.
"Let's test your Taijutsu," Yagami commanded. "I want to see if your constitution has actually evolved."
After a brief, intense sparring session, Yagami confirmed the improvement. Gorilla's strength and speed had leaped forward. However, Yagami's Byakugan noticed a slight hitch in Gorilla's right shoulder during a high-speed back-swing.
"Stop," Yagami ordered. "Roll up your sleeve."
The muscle tissue around the bicep and shoulder was discolored—not a bruise, but a deep, structural strain.
"It seems this 'overclocking' has a price," Yagami noted grimly. "Chakra stimulation causes cellular micro-tears and internal friction. You can't just power through this; you need professional medical intervention to ensure these small injuries don't become permanent disabilities."
Training in the shinobi world was a resource-heavy endeavor. Without a master to guide the flow or a medic to mend the damage, blind "hard work" often resulted in a broken body. Many ninja died because a legacy of old injuries made them a millisecond too slow to dodge a kunai they should have seen coming.
Yagami took Gorilla to the camp's medical wing to see Senju Mie. After the political medical malpractice drama Yagami had orchestrated for her in the past, he felt a twinge of guilt, but she was undoubtedly the best medical Jonin available.
After a thorough examination, Mie turned to Gorilla with a scolding glare. "This is reckless. You're forcing your cells to work at a rate they aren't built for. You have dozens of 'shadow injuries'—tiny ruptures that haven't manifested as pain yet but are rotting your foundations."
She gathered glowing green medical chakra in her palms and began the delicate process of knitting Gorilla's cellular structure back together. It took twenty minutes of focused treatment.
"Try the movement again," she said, wiping sweat from her brow.
Gorilla moved his arm; the stiffness was gone. He felt light, refreshed. As they left the tent, the weight of the moment settled on him.
"I thought it was just muscle strain," Yagami said as they walked. "But those 'shadow injuries' are dangerous. Gorilla, no more 'three-a-day' sessions. Being 'durable' is a talent in itself, and your body isn't built like a kage's. This breakthrough cannot be rushed."
He stopped and looked his subordinate in the eye. "I gave you the Cross Seal so you could stand taller, not so you could cripple yourself for my sake."
Gorilla looked at the gloved back of his hand, where the seal lay hidden. "Captain... three months ago, I reached my limit. Knowing that no matter how hard I bled, I wouldn't get a single drop stronger... it was a despair I can't describe. I was terrified every day that the division would leave me behind. I stopped sparring because I didn't want the others to see I was standing still."
He looked up, his voice thick with emotion. "You gave me hope. You showed me that effort still matters. What are a few shadow injuries compared to the chance to keep standing by your side? Thank you, Captain."
Yagami sighed, moved by the man's loyalty but firm in his caution. "I'm not telling you to stop working hard. I'm telling you to control the rhythm. Two days of rest for every one day of stimulation. Use the medics. If you turn into a burnt-out husk, you're of no use to me. You've been with me through the Land of Rivers, Whirlpool, and Rain. In the ANBU, surviving a year is an eternity. I want you to keep surviving."
"I understand, Captain," Gorilla vowed. "Two days. I'll follow the rhythm."
...
Later that afternoon, Yagami summoned the White Sheep and Flower Deer squads to a clearing outside the camp. The members—Leaf Monkey, Pintail, Antelope, and the others—gathered around, sensing the gravity of the meeting.
"I've been 'secretly' working on something with Gorilla," Yagami said, sitting on a weathered stone. "I think you've all noticed the change in him. I've developed a specialized sealing technique to enhance your combat capacity. I call it the Cross Seal."
The air grew still. The team had seen Gorilla's " Enhanced" Thorn Forest and were already buzzing with questions.
"You are the veterans of this division," Yagami continued. "You've followed me through five different lands and twice as many battlefields. I considered setting up a formal exam for this, but honestly? Your loyalty and your records are all the 'exam' I need. The Cross Seal will be our hallmark. It will be the bond that ties this division together. Gorilla, show them what you've found."
As Gorilla stepped forward to demonstrate, the eyes of the ANBU under the masks lit up with a mix of awe and ambition. They knew their Captain was strong—some whispered he was a hidden "Elite Jonin"—but seeing him master and distribute a proprietary high-level sealing art solidified their conviction. They weren't just a squad anymore; they were becoming something much more formidable.