Liang Qiu initially refused permission. "The Forbidden Abyss has claimed the lives of dozens of our disciples. I won't send two of our most promising cultivators to almost certain death."
But Master Jian intervened. "They're going to advance one way or another. Better in the Abyss where time dilation gives them years of cultivation in months, than out here where enemies keep trying to kill them."
After three days of debate, Liang Qiu relented with conditions: they could enter for one year outside time (ten years inside), they'd carry emergency escape talismans, and they'd report via communication array monthly.
The Forbidden Abyss was located deep beneath Azure Sky Mountain, accessible only through ancient formations. The entrance was a swirling portal of chaotic energy that hurt to look at.
"Last chance to back out," Kai said.
"Not a chance," Yuhan replied.
They stepped through together.
The world twisted. Reality inverted. When their senses returned, they stood in a vast underground cavern where spiritual energy was so dense it was visible as glowing mist. The cavern stretched endlessly in all directions, filled with dangerous spirit beasts, natural formations that could kill careless cultivators, and treasures hidden throughout.
Time moved strangely here. Kai could feel it—each heartbeat lasted subjectively longer, allowing deeper meditation and faster advancement.
"Ten years," Yuhan said, looking around. "We have ten years to become as strong as possible."
"Then let's not waste time."
The first year (one month outside) was brutal. They fought spirit beasts daily, some at Nascent Soul level. They cultivated in areas where spiritual energy was so concentrated it burned their meridians, forcing adaptation.
By the end of year one, both had stabilized at Core Formation peak, ready for Nascent Soul breakthrough.
The second year, they attempted Nascent Soul tribulation together. The Abyss's strange physics made the tribulation even more intense, but they supported each other through it.
When the tribulation cleared, they'd both broken through. Nascent Soul realm at age seventeen (physically), though technically nineteen counting Abyss time.
Years three through five were spent consolidating their foundation, learning to wield Nascent Soul powers properly. They discovered ancient cultivation manuals hidden in the Abyss, techniques from forgotten ages that perfectly complemented their abilities.
Year six, they encountered another cultivator in the Abyss—an old man who'd been trapped there for decades, having lost his way out. He was at Soul Transformation realm but weak from isolation and resource depletion.
"You're... young," the old man rasped. "How long have you been here?"
"Six years," Kai answered.
"Six years and you're already Nascent Soul?" The man laughed bitterly. "I was Nascent Soul when I entered forty years ago. Thought I'd reach Soul Transformation and become legend. Instead, I'm dying slowly in this place."
"We can help you get out," Yuhan offered. "We have navigation techniques."
The old man studied them. "Why would you help me? In the cultivation world, everyone looks out for themselves."
"Because we're trying to change that world," Kai said simply.
They spent three months nursing the old man back to health, sharing their resources. In return, he taught them Soul Transformation techniques, explaining principles they'd need for their next breakthrough.
"You two remind me of why I started cultivating," he said before they parted ways. "Not for power, but to protect what mattered. Don't lose that. The higher you climb, the easier it is to forget."
"We won't," Yuhan promised.
Year seven and eight were spent hunting for specific resources they'd need for Soul Transformation breakthrough. The Abyss was vast, containing treasures from ancient ages. They found spirit herbs that hadn't existed in the outside world for millennia, crystallized time energy, fragments of shattered immortal artifacts.
Year nine, they attempted Soul Transformation tribulation.
This tribulation was qualitatively different from previous ones. It didn't just test their physical bodies and spiritual energy—it tested their souls, their understanding of the dao, their very reason for cultivating.
Kai faced visions of his previous life. Every mistake, every person he'd failed to save, every moment of weakness. The tribulation asked: Are you worthy of transcendent power? Will you use it to become a tyrant again?
"No," Kai answered. "I've learned. I understand now that power without compassion, strength without connection—these are empty. I cultivate not to stand above others but to stand beside them. To protect, not rule."
The tribulation accepted his answer. His soul transformed, expanding, becoming something more than mortal.
Yuhan faced different visions—his own previous life, his regrets, his fear of loss. The tribulation asked: What is the purpose of the sword? To cut, or to protect?
"Both," Yuhan answered. "A sword cuts what threatens those it protects. My blade exists not for glory or pride, but for the people I love. For the world I want to see."
His soul transformed as well, sword intent merging with his very essence.
When the tribulation cleared, they'd both reached Soul Transformation realm. At age seventeen (physically), they'd achieved what took most cultivators a century or more.
The final year in the Abyss was spent stabilizing and preparing to return. They practiced techniques that would shock the cultivation world. They made plans for preventing the Chaos Wars. They trained until their coordination was flawless.
And in quiet moments between training, they simply existed together. Talking, meditating, experiencing the simple joy of each other's presence.
"Do you think we can really do it?" Yuhan asked one night. "Save everyone? Prevent the wars?"
"I don't know," Kai admitted. "Every action we take creates new ripples. We might save some people and doom others. But I know we have to try. Because the alternative—doing nothing while knowing what's coming—would destroy us."
"Together then. Whatever happens."
"Together. Always."
On the last day before their scheduled exit, they stood at the portal back to the outside world.
"One year passed out there," Kai said. "We've been gone twelve months. But we've lived ten years in here. We're different people now."
"Better people, I hope."
"Stronger, certainly. Whether that's better..." Kai took Yuhan's hand. "We'll find out soon enough."
They stepped through the portal together.