Mark can feel his reinforced heart continue to change as it greedily absorbs the Qi that is constantly delivered by the blood. In turn, it pumps that Qi enriched blood throughout the whole body.
Nice, nobody ever complained about a passive strength increase, however small that increase is.
And that was indeed the case, even if the rest of his body hadn't been optimized yet, his DNA still enabled his cells to intake and process that Qi. Every cell in his body was slowly absorbing Qi and optimizing itself. In theory, he could sit around for a couple years, doing nothing but some focused breathing, and finish the Qi Refining stage.
Looking over at his phone, he sees that it's only the early afternoon, and from the screams of pain his ears periodically picked up across the house, it's safe to assume his parents were in the middle of cultivation. Good luck… you're gonna need it.
With nothing else to do, he dives right back into cultivation. No point in delaying, the sooner we can become more powerful, the sooner we can begin our plan for world domination…
"Mwahahahahaha… AHAHAHAHAHAHAHA!" He puts one hand over his face, "The world will rue the day it crossed Mark Knight!"
Looking around his room to see no one's there, he deflates. It's less fun when no one hears your awesome evil laugh and stereotypical villainous vague declaration of revenge on the world.
He seems to forget that he should be cultivating, as he descends into a daydream where he has a fantastical conspiratorial secret society targeting him and he fends them off with the dragon sealed in his arm. Dark Reunion!
It took five whole minutes for him to remember to get back on schedule. Come on, Mark. Lock in. I'll just watch Saiki K. later. Lungs next.
That thought alone makes Mark pause longer than he expected as his mind churned through all the details of this endeavor. Fucking with the heart was dangerous, but at least it kept working on its own; it was surprisingly sturdy considering the amount of people who die of heart disease yearly.
The lungs were different. They were fragile in a way most people never had to think about. You didn't usually die from a chest wound because you lost too much blood. You died because the lung failed, because air or fluid filled the space it needed to expand, because the pressure crushed it in on itself until breathing became impossible.
A collapsed lung and subsequent internal drowning. Yep. That's the shit that'll kill ya quick, and I'm doing it voluntarily… yay.
He exhales slowly and visualizes them anyway. The pair of spongy masses filling his chest, branching bronchi like inverted trees, alveoli folded in on themselves to maximize surface area. Millions of microscopic sacs inflating and deflating in steady rhythm. The lungs are one of the true treasures of evolution, they work because the internal pressure is just right. Change that balance too much and the whole system fails catastrophically.
The problem becomes obvious immediately. Tempering with the established method means pressure. Pressure means constriction. Constrict the lungs too much and they stop expanding. Worse, compress the space around them unevenly and the tissue could fold inward, collapse, or flood itself with blood and fluid as vessels rupture under strain.
There was no clever workaround for that. Either he accepted controlled suffocation for short periods, or he didn't temper the lungs at all.
Mark sits cross-legged on the bed and takes a deep breath, filling his chest as fully as he can. He holds it, feeling the stretch in his ribs and the slight burn as the air settles deep, then releases it slowly. Again. And again. He commits the sensation to memory, the exact limit before discomfort becomes alarm.
Pressure without imbalance. If they collapse, I'm fucked.
He gathers Qi and lets it pool around the lungs, careful this time to distribute it evenly. Not squeezing from one side or pinching inward, but pressing uniformly from all directions, like submerging them in something heavy and invisible.
He inhales once more and holds it as the Qi density increases.
The effect is immediate and wrong in a way his instincts hate. His chest tightens, expansion arrested halfway through the breath. The lungs try to inflate further and fail, air trapped inside them as the surrounding pressure refuses to yield.
Just a few seconds pass and the suffocation hits faster than he expects. Not panic yet, but a sharp, escalating demand to breathe that overrides rational thought. His diaphragm jerks uselessly against the resistance, muscles contracting with nowhere to go. Pressure builds behind his sternum, and a his senses flare in warning as the urge for air begins to override all other thought in his brain.
Too much and they fold. Too long and they flood. Fuck, fuck, fuck, come on, gotta get this just right. COME ON!
He holds the Qi steady anyway, refusing to let it shift or change. His eyes bulge as the lungs strain against the compression, tissue working harder to exchange oxygen under worse conditions, alveoli forced to operate under stress they were never meant to endure.
Heat blooms behind his eyes. His heartbeat accelerates, blood pounding louder in his ears as oxygen levels drop. A cold tightness spreads through his chest, a subtle heaviness that sends a spike of fear through him. This wasn't like holding your breath, it was like drowning in molasses.
That's it. Any further and something gives. Mark quickly releases the Qi.
The pressure vanishes, and his lungs surge outward violently. Mark immediately regrets his decision, his mind racing into overdrive the instant he realizes what he did. Shit, I should've considered the pressure differential.
Air rushes in, ragged and uncontrolled, followed by a wet cough as his chest spasms. He gasps again, then again, hunched forward as his body fights to reestablish equilibrium. For a terrifying moment, every breath feels thick, like he's pulling air through water. He doubles forward, hands braced against the mattress, saliva and bloody froth dripping onto the sheets.
He coughed and tasted salt and iron. The sound that came from his chest was wrong, a low, bubbling rasp that followed every breath. It felt like his lungs were flooding from the inside, the airspace refusing to give way to something he could not push out.
Several minutes later, the feeling fades as normal breathing resumes. He stays still, breathing shallowly, refusing to circulate Qi into the lungs while they recover. The ache that follows is deep and spreading, a soreness that lingers with every inhale, but there is no crackling, no gurgling, no uneven pull, no sense of collapse, just a lingering burn in the nose. The danger had passed, but he wasn't finished.
They held, thank fucking God.
After a few more minutes, once his breathing steadies and the heaviness fades, Mark takes one final clean breath of air before gathering Qi again, stopping well short of the previous density. The pressure returns, firm but controlled, compressing the lungs without locking them completely. He breathes shallowly against it, letting the tissue adapt rather than fight. He doesn't forget to gradually dissipate the Qi this time.
It's more like breathing when scuba diving, like a weight was is sitting on my chest rather than straight up drowning.
The third pass is lighter still. The Qi presses gently, consistently, for a much longer duration. His breathing slows, controlled and efficient, lungs learning to function under constraint instead of resisting it.
When he finally disperses the Qi for the last time, Mark lies back on the bed, staring at the ceiling as his chest rises and falls.
Each breath feels deeper now. Stronger. Like his lungs have learned how to draw more than just oxygen, nitrogen, and other gases from the air. He can feel Qi get drawn with every breath; he no longer needs to semi-consciously draw it in, it's purely automatic now.
Good. No drowning, no collapse, and no more brain power used on taking in Qi, I see this as an absolute win.
He exhales slowly, a grin creeping onto his face despite the lingering soreness and exhaustion from tempering two organs in less than half a day.
"That is enough torture, I mean, cultivation for the day, I require food, rest, and entertainment!" He declares into the void as if addressing his subjects… then immediately falls asleep.
…
"Give the people bread and circuses and they will never revolt," Mark sighs as he checks the time to see he's on his second hour of doomscrolling on TikTok while munching on honey-mustard pretzel sticks. "Damn, these are good though…"
It was the next day after his eventful double whammy of cultivation and Mark wanted nothing to do with messing around with his organs for the next twenty four hours. Instead, he'd take a sort of sadistic pleasure in hearing about the struggles of those he's granted superhuman capabilities to.
"Mark. We need to have a talk about the… pain level. In your manual, you said that you took only thirty minutes to do the first Marrow Cleansing, and when I saw your father finish in that time, I thought it'd only take that long. But I've been doing it on and off for easily forty five minutes at this point. I can't keep this up." Grace was once bitten and twice shy, and now very hesitant to continue. It's not easy to force yourself to continue doing something that you know will hurt, especially when it's optional. It's not in human nature, simple self-preservation.
"Hmm…" Mark sinks into a deep contemplation. Maybe that's the benefit of doing it in one go. You have a lower net amount of time at the cost of enduring an astronomical amount of pain in one sitting. "I think I understand what's happening, I'll need more people to get back to me on their progress first, but for now, just do it at the pace that's comfortable for you. Don't give up, though. Keep recording the total amount of time you've cultivated for and when you're completely done, let me know what the final time is."
Grace sinks deeper into the couch, folds her arms, and cuddles up to William, obviously unhappy with that answer. "Fine."
Gulp.
Mark eyes his father, trying to get him to help him out here. William suddenly finds the ceiling very interesting, desperately trying not to bring any attention to himself. No need to gloat about finishing in thirty minutes more than he already did.
"Well… uh, let me know. I'm gonna… get back to it, I guess. When I finish up with my organs, I'll update the manual and send it out." Mark makes a quick escape from his upset mother, not eager to deal with a newly energetic and much stronger female authority figure in his house.
Returning to his room, he sees his ruined sheets and decides that tidying up, doing laundry, and getting some R&R is much more important than putting himself through another cycle on the torture wheel that is cultivation.