The challenge in guiding mana to his bone marrow production sites was not in the movement of mana from his heart to his femur, but rather, in what came next.
Just like how the body had large blood vessels like veins and arteries and then much smaller and finer blood vessels like capillaries, the same also held true for a body's mana distribution system.
The body had a main pathway to move mana, known as the mana circuit, which was like a smooth highway that moved mana to each major organ, however, the part where this highway ended, the mana circuit branched into several dozen smaller and finer pathways which could handle a very limited amount of mana load at a time.
The bone marrow was a specific organ that was connected to the main mana circuit via hundreds of these fine, small, mana passages that could only transport a very limited amount of mana at once, which proved to be a major challenge for Leo.
As per the scroll, he was supposed to begin giving the bone marrow a steady supply of mana, however, this step was easier said than done, as once he was done moving the entire mana pool he had gathered near his heart to his femur, moving them down these fine channels without damaging them was a very tall task.
It was like trying to divert a raging tsunami through small irrigation channels carved by farmers to water their crops. The force of the mana surging through his body was immense, a torrential flood that threatened to overwhelm the delicate pathways branching from the main circuit.
Leo could feel the raw power of his mana, a relentless tide crashing against the narrow passages leading to his bone marrow, straining the delicate balance.
Each time he attempted to push a larger portion of mana through, he could almost feel the channels quiver, as if they might burst from the pressure and this scared him immensely.
The technique warned that if he did not have a precise control of mana, it might end up temporarily injuring him and Leo did not wish for such an outcome.
He had to think carefully, almost like a farmer standing by the river, as he held back the floodwaters, releasing just enough through the carefully constructed channels to nourish his fields without destroying them.
The trick was to guide the mana in precise amounts, was to let it trickle like water, flowing smoothly into each narrow capillary without overwhelming them.
Yet, unlike water, mana was alive, pulsing with energy and power that resisted being controlled.
It required finesse, patience, and an acute awareness of every movement within and if Leo had not already gained a significant control over his body's mana via the mind meditation manual, he might have failed in his very first attempt to control things here.
Thanks to his mastery of the mind meditation manual, Leo could now visualize the mana moving through his body as a shimmering blue current, swirling and pushing against the barriers of the tiny passages.
The goal wasn't to force the mana through but to guide it, shaping its flow to match the capacity of the channels.
He had to be patient, he had to go slow, ensuring that he did not burst any pathway through extreme load, but still facilitated the transfer that was necessary.
As he continued, sweat formed on his brow. Each drop of mana, each careful adjustment, was like the farmer adjusting the flow of water, knowing that too much or too little could either flood the fields or leave them dry and barren, until the text on the meditation manual finally showed a subtle change.
[ You have successfully started the process of bone marrow modification. Hold this flow steady for the next 4 hours to produce 1000 new hybrid cells…. ]
Leo almost spat a mouthful of blood when he saw this text.
After great troubles, the manual finally recognised his efforts and notified him that the process of starting the production of hybrid cells had begun, however, the production rate was nowhere near satisfactory.
His body had trillions of cells, and billions of them were red blood cells that carried oxygen from his lungs to all the other individual cells in his body, and producing just 1000/ four hours of such gruesome meditation was nowhere near an enough replacement rate required to eventually cycle them out of his body.
'1000 is too low…. I won't even feel the difference with such a slow success rate, however, I can't overload my mana channels anymore.
If I try to speed things up by letting more mana through, I'll end up causing irreversible damage to my mana veins.
I cannot speed things up anymore' Leo thought, as he was self aware about his own limitations.
Although part of him was eager to speed up the process, Leo knew that rushing would only lead to injury. Despite his frustration with the slow progress, he remained patient. Over the next four hours, he carefully channeled the mana gathered near his femur until it was fully expended, resulting in the creation of just 1,000 new cells.
Exhausted, Leo felt the toll the session had taken on him.
His limbs were heavy, weighed down by the strain of maintaining control for so long.
His mana reserves were nearly depleted, leaving a hollow emptiness in his core that made every breath feel shallow and labored.
His mind, too, was frayed, as if he'd been balancing on a razor's edge for hours and his body throbbed with a dull ache, especially around his femur, where the concentrated mana had flowed.
It wasn't pain exactly, but a deep-seated fatigue, like a muscle pushed beyond its limit.
As he flexed his fingers, he could feel the slight tremor in them as the aftershocks of intense focus ran through his system.
Closing his eyes, Leo let his awareness sweep through his body, assessing the damage.
For now, nothing seemed out of place—no ruptured mana channels, no internal injuries—but the subtle warning signs of overexertion were there. His stamina had been sapped, his mana reserves drained to a dangerous low and his mental energy was frayed, making his thoughts sluggish.
"That took more out of me than I expected," he murmured to himself, feeling the weight of exhaustion pull him down as he realized that practicing this meditation technique was much more dangerous and taxing than the mind meditation manual and the results were different too.