Karin placed both hands upon her knees and straightened her back.
She began by creating an extremely small quantity of chakra.
Physical energy rose from her living cells.
Spiritual energy answered from her mind.
They entered her chakra network and combined.
Karin carefully observed the process.
Elite Shinobi created chakra almost instinctively. They rarely separated the two components within their perception once the mixture had formed.
She felt the physical component.
Warm and Vigorous.
Closely connected to the immense vitality of the Uzumaki body.
She felt the spiritual component.
Sharp and Cold.
Formed from memory, Soul, and Intent.
Then Karin opened herself to the energy surrounding the forest.
A thread of Natural Energy touched her skin.
She attempted to draw it directly into her chakra network.
She attempted to draw it directly into her chakra network.
The result was immediate.
The natural energy surged through several open tenketsu and flooded her coils.
Karin's eyes snapped open completely bloodshot.
Her body became rigid as the uncontrolled energy collided with her chakra.
For a heartbeat, nothing happened.
Then the muscles in her right forearm convulsed.
The flesh beneath her skin swelled violently.
Veins rose across her arm like thick cords. Her fingers lengthened unevenly as the bones inside them shifted, accompanied by a series of wet cracks. The skin darkened from pale flesh to a mottled reddish-purple.
Karin could merely stare blanky losing control of her body as her arm expanded.
Muscle layered over muscle without structure or purpose. Flesh bulged outward in pulsing masses, causing her forearm to inflate until it was almost as thick as her torso.
Her sleeve tore apart.
One side of the swollen limb split open, revealing glistening red tissue beneath the skin. New muscle fibers twisted over one another like worms, forming and dissolving faster than her body could stabilize them.
The mutation began spreading toward her shoulder before Karin finally managed to snap back.
Realising what was happening she immediantly understood.
Her overwhelming Yang vitality was reacting to the excess natural energy by creating life without restraint.
Cells multiplied without purpose.
Muscle expanded without balance.
Her body was trying to adapt to power it could not contain, transforming itself into whatever shape might survive the pressure.
If she allowed it to continue, she would become a mass of uncontrolled flesh and die.
Karin clenched her teeth and forced every available tenketsu open.
"Out."
The excess natural energy resisted.
Her swollen arm expanded again, the flesh inflating like a grotesque balloon. Her fingers fused together for an instant before separating into several uneven digits.
Dark markings crawled across her shoulder and neck.
"Get out!"
A violent pulse erupted from her body.
Leaves tore free from nearby branches.
The surface of the river exploded into mist.
Natural energy burst from her tenketsu in a visible distortion of air onto the grassy patch in front of her creating a vibrant field of blooming flowers.
The mutation stopped.
Then the swollen flesh began to collapse.
Muscle fibres withdrew beneath her skin. The grotesque masses softened and shrank as the excess tissue broke down. Her arm gradually returned to its original size.
The additional digits dissolved.
Her bones shifted back into place with several sharp cracks.
The reddish-purple discoloration faded until her skin became pale once more.
Karin remained seated, breathing heavily.
Her right arm trembled uncontrollably.
Thin streams of blood ran from the places where her skin had torn.
She exhaled and inhaled extremly fast like someone having a panic attack.
"Too much."
Natural energy itself was not hostile.
The danger came from the nature of her body.
Karin's Uzumaki vitality reacted violently
When overwhelmed by natural energy, her body attempted to survive through adaptation and uncontrolled growth.
It produced more flesh.
More muscle.
More life.
Without structure, that life became nothing more than a fleshy abomination.
Karin slowly flexed her restored fingers.
The stronger and more adaptable the malformed body became, the harder it might be to return to human form.