Outside the room, listening to Kushina's soft whimpers, Tsunade felt increasingly miserable. It got to the point where she began to feel jealous of Kushina and resent Saiki, thinking of him as a lecherous little bastard.
But the reality was quite the opposite. She had reason to be jealous of Kushina, because Kushina was genuinely experiencing pleasure. For Saiki, however, this was pure suffering.
His Innate Qi divided into Yin and Yang, cycling through both their bodies. Yin birthed Yang at its extreme, and Yang birthed Yin. However, with every cycle, that vital energy diminished slightly, consumed to repair Kushina's soul.
This "breath" of energy was the crystallized essence of Saiki's vitality, spirit, and soul. By doing this, he was literally burning his own lifespan to save hers.
Because she was so embarrassed, Kushina buried her face in Saiki's shoulder, completely failing to notice his increasingly deathly pallor.
Saiki was silently keeping count. Sixty-four cycles complete. About seventeen more, and he could end this session of Dual Cultivation.
It didn't strictly have to be eighty-one cycles (9x9), but his intuition told him that was the optimal number.
However, he was beyond exhausted. It felt like he hadn't eaten for two days and was then forced to do heavy manual labor for twenty-four hours straight. He couldn't muster an ounce of strength.
And that wasn't all. While Kushina's injuries were being repaired and her condition was improving, she was also expending stamina. She had reached her physical limit and no longer had the strength to move her hips. Saiki was forced to simultaneously circulate their energies and manually lift and lower her by her plump, peach-like buttocks to assist the rhythm.
One rise and fall constituted a single cycle. In reality, Kushina's vertical movements acted like a pressurized pump. The speed and force of the physical stimulation dictated the speed of the internal energy cycle.
Because the level of stimulation varied with each cycle, Kushina required anywhere from a dozen to several dozen thrusts per cycle. Given her current physical state, this was an immense burden on her.
Hold on. Just hold on! Saiki screamed at himself internally. He gritted his teeth, his ten fingers sinking slightly into the soft flesh of her buttocks. There was no turning back now; he had to see this through to the end, no matter what.
Based on his current calculations, he would suffer severe damage to his vitality when this ended, requiring a long period of recuperation. But he refused to leave any lingering defects in Kushina's body.
Sometimes, reality doesn't bend to sheer willpower. With just two cycles remaining, Saiki's ears began to ring, and his vision started to tunnel into darkness. He was on the verge of passing out.
I can't give up. This thought was firmer in Saiki's mind than ever before. Without overthinking it, he tilted his head back, opened his mouth, and inhaled sharply. The Auspicious Cloud hovering above him—which was formed from a portion of his own Innate Qi—was sucked into his mouth, instantly fueling the final two cycles.
Saiki's cultivation involved refining a single breath of Innate Qi. This breath was the condensation of his vitality and spirit. It grew stronger by absorbing the essence of the sun and moon, and natural energy. After embarking on the path of Dual Cultivation, absorbing the Yin-natured energy from women also strengthened it.
Sage Chakra was merely a byproduct of his absorption of natural energy. The conversion rate of natural energy into Innate Qi was abysmal; otherwise, he wouldn't need to train so hard. He could just casually absorb natural energy and become a god.
Of course, Sage Chakra also served to nourish his Innate Qi. It was like fish and water: water isn't the fish, but water sustains the fish, and the fish cannot survive without water.
Now he had really done it. By absorbing the Auspicious Cloud—which he used to assist in absorbing natural energy and creating Sage Chakra—and converting it back into raw Qi, he was essentially draining the water and bleeding the fish dry. Saiki had hit his absolute, rock-bottom limit.
Forcing himself to hold onto that last breath of energy, and coordinating with Kushina's movements, he completed the final two cycles. For the first time in his life, Saiki actively wished for sex to end sooner.
When the meager remnants of his circulating Qi finally returned to his body, Saiki's ears were filled with a deafening ring. His vision was completely black; he couldn't see a thing. He was holding on through sheer, desperate willpower.
Exactly as Saiki had anticipated, upon completing the second set of eighty-one cycles, Kushina felt completely reborn. Aside from severe physical exhaustion and a feeling of being drained of stamina, every trace of discomfort in her body had vanished. She felt better than she ever had in her life.
And why wouldn't she?
That breath of Qi represented the entirety of Saiki's four-plus years of relentless cultivation. He had essentially given it all to her. Not only was her body fully healed, but once she rested and fully absorbed what Saiki had given her, she would rapidly ascend to the Super Kage level.
Saiki, on the other hand, was in a terrible state. He had no idea how long it would take to cultivate his way back to where he had been.
Fortunately, he was now on the path of Dual Cultivation. Having already "Entered the Path," retracing his steps with the aid of Dual Cultivation meant it wouldn't take another four years.
Since he had already Entered the Path, that single breath of Innate Qi was still functional, so his combat strength wouldn't drop too drastically.
However, Qi was his foundation. Right now, that foundation was dangerously unstable. His speed in absorbing natural energy would plummet, and the Sage Chakra he had expended would be incredibly difficult to replenish.
Sitting astride Saiki, leaning against his shoulder as she caught her breath, Kushina was wondering how to end this awkward situation. Suddenly, the Saiki she was holding onto slumped backward. Weak and exhausted, she was pulled down with him, collapsing onto his chest.
Her heart pounded. During the Dual Cultivation, she had climaxed three times, yet Saiki remained fully engorged. Kushina thought Saiki was just bullying her, and she felt impossibly shy.
After lying on Saiki's chest for a while, seeing that he wasn't making any moves, Kushina struggled slightly before whispering bashfully, "Sai... Saiki, are you still not finished? I... I can still go."
If Saiki had been awake, he would have found this highly amusing. He would definitely have thought, Kushina may be pure, but she's not entirely clueless. She's a woman of marrying age, after all, and girls in the Shinobi World mature early. Unfortunately, he currently looked like a corpse.
Uttering such shameful words meant Kushina had accepted him, and she was already trying hard to fulfill her duties as a "wife." But Saiki didn't respond.
After waiting a moment longer without a reply, Kushina felt like Saiki was teasing her again. She had tried so hard! Feeling a bit peeved, Kushina used her hands to push herself up.
"Saiki?!" A panicked scream echoed through the room. As she pulled back, she saw Saiki's condition. He looked worse than terrible. The privacy barrier he had set up had already failed due to a lack of chakra to maintain it. Outside, a distressed Tsunade, sitting on the hallway bench, heard the scream without even needing to focus her senses.
"Saiki, are you okay? Don't scare me!"
Hearing Kushina's panicked scream, Tsunade shot up and tried to push the door open, but it was locked. Hearing the sob in Kushina's voice from inside, Tsunade simply kicked the door off its hinges.
"What's wrong? What happened to Saiki?" Bursting into the room, Tsunade completely lost the composure expected of a veteran medical ninja, her voice frantic.
Seeing Tsunade rush in, Kushina, terrified, also realized she was completely naked. Sniffling, she cried, "I don't know! Saiki seems really wrong! He won't wake up no matter what I do!"
Tsunade didn't bother listening to Kushina's explanation. She slapped a hand onto Saiki's lower abdomen and immediately began her examination.
One scan was all it took for Tsunade to realize the situation was catastrophic. When Saiki had suffered his previous backlash, his internal chakra had been a raging tempest. Now, the chakra inside his body was like a pool of stagnant, dead water.
Saiki still possessed chakra in his body; what he had exhausted was his vital breath of Qi and his Sage Chakra.
A normal person's chakra flows through their body like blood. Saiki's current stagnant state meant he was truly standing on death's door.
In reality, he wasn't going to die; he would likely just be comatose for a long time. But the diagnosis terrified Tsunade.
Tsunade understood Saiki's condition better than anyone. She quickly formulated an emergency treatment plan. She created a Shadow Clone to guard the broken doorway, then hoisted Saiki up and moved him to the other bed in the room.
Although Kushina was in a premium ICU suite, Konoha wasn't wealthy enough to have that many private, single-occupancy rooms.