The battle against Rien actually grew simpler after she transformed into her Kishikai form.
Takatsuki went so far as to completely drop the defenses around his body, taking Rien's strikes head-on.
Rien, meanwhile, was on the verge of a total psychological breakdown.
She could not comprehend why her attacks failed to inflict even the slightest bit of damage on him.
Every single one of her blows was capable of instantly snuffed out a human's life, yet hitting Takatsuki was like throwing rocks into the fathomless sea—disappearing completely without a trace.
She didn't stop to think deeper, merely assuming Takatsuki was using some incomprehensible method to negate her attacks.
This only made her offense all the more ferocious. Relying on the terrifying regenerative speed of her Kishikai state, and knowing Takatsuki's attributes didn't counter hers, she attempted to trade flesh for flesh to bring him down.
Takatsuki ignored her incoming strikes entirely, matching her trade for trade as he continuously projected weapons and impaled them straight into her body.
The energy within Rien's Kishikai form was immense. Takatsuki had previously tried to erase her outright using Killer Queen's ability, but it failed—or rather, Killer Queen's rate of destruction couldn't keep pace with Rien's absurd regenerative speed.
"Why?! Why won't you die?!"
Rien had gone completely wild. Unlike Takatsuki, who knew exactly why he couldn't kill her, Rien was encountering something utterly beyond her understanding for the very first time.
Why were her attacks useless? Not blocked, not defended—simply devoid of effect, as though they had never been launched at all.
Gritting her teeth, she frantically stoked the Tao within her body, her aura surging to unprecedented heights.
"Oh! So there's this trick, too!"
Suddenly, as if a thought had just struck him, Takatsuki reacted.
Although Rien didn't know what Takatsuki had done, she felt her own Tao rapidly draining away.
It was like a wooden bucket with a gaping hole punched into its side.
"What... did you do?!"
Rien's eyes widened as she reached out to grab Takatsuki, only for another sword to pierce through her arm and pin it firmly to the ground.
"Shh. Quiet down."
Rien felt more than just the sharp blades pinning her down like stakes—something heavy was pressing down mercilessly on her head from above.
And her draining Tao was pouring out rapidly from that exact spot.
Heaven Stairway · D4C: Love Train!
A power he rarely relied on, but one that proved remarkably useful.
Takatsuki had used it to absorb vast reserves of energy before, though absorbing energy from a living organism usually required the target's consent.
Unlike inanimate objects, absorbing energy from a conscious, living being invited intense resistance. Thus, while he had caught Rien completely off guard at first, once she regained her senses, Heaven Stairway's absorption speed ground to a sluggish crawl.
He... couldn't drain her any faster!
"Vile human!"
Though her body was pinned, Rien shuddered violently, forcefully snapping off...
...her own arms.
A brand-new pair of arms sprouted out instantly and formed a hand seal. The Tao within her body fluctuated as she activated a Taoist art she had researched over a millennium.
Takatsuki felt the ground beneath him suddenly go empty, and the suppressed Rien vanished in a split second.
"A Taoist art?"
Takatsuki was naturally familiar with Taoist arts—he had seen plenty of them within Mu Dan's memories. Most were fairly crude, such as condensing Tao around the body to strike, manipulating Tao to form footholds, or thinning out one's Tao to achieve invisibility.
These techniques were useless against Takatsuki, as he possessed far more effective means to achieve the exact same results.
"Vile human! I've changed my mind—I won't even bother turning you into an Elixir!"
Rien had originally intended to refine Takatsuki into a top-grade Elixir, but after taking such an absolute beatdown, she abandoned the thought entirely.
In truth, it was more that she realized she simply could not subdue the man before her.
"Hey, hey, is that really okay? You've still got plenty of swords sticking out of you, you know."
A Tensen's body felt no pain, so Rien hadn't bothered to pull the swords out.
She was simply relying on her body's natural regenerative pressure to slowly push the weapons out on their own.
Although a Tensen restored themselves quickly, this particular process wasn't fast. Ignoring Takatsuki's warning, her hands formed another seal.
"Broken Phantasm..."
Seeing that Rien had no intention of pulling the blades out, Takatsuki uttered a low whisper. A violent explosion detonated instantly across her body.
Broken Phantasm—a technique he hadn't used in a long time. Compared to his other abilities, its raw destructive power was relatively weak, but when quantity stacked into quality, it was still terrifyingly lethal.
The violent blast tore Rien's body apart in a single moment. The shockwave of the explosion even blew away the surrounding rooftops.
"─────!"
Rien could no longer speak. In her Kishikai form, her core was the ovule located in her Tanden. The explosion had completely destroyed her body, leaving only a single ovule surviving in the wreckage.
Just as a dense cluster of vines began sprouting from the ovule, a hand suddenly plunged into the center of the blast, snatching the regenerating ovule firmly.
"Goodnight, Rien..."
Heaven Stairway's arm manifested, overlapping with Takatsuki's. Killer Queen's ability activated, reducing the palm-sized ovule directly to fine ash.
The battle against Rien was frankly boring. Her combat style was nothing more than brute force and sheer output. Had it been Ran, Takatsuki might have had some interest in trading moves slowly, but unfortunately, Ran himself had been too weak.
Having eliminated Rien, Takatsuki descended from the sky, landing near a young man standing off to the side.
"Are you here to block my path as well? Gui Fa."
Gui Fa held a book in front of his face, concealing his features completely.
Only upon hearing Takatsuki's voice did he lower it: "The Tan Flowers are this way."
Without elaborate explanations, Gui Fa turned and led Takatsuki toward the distance.
Though he found it curious, Takatsuki didn't attack Gui Fa, choosing instead to follow him deeper into Horai.
The two passed through numerous palaces as if taking a stroll. As they walked, Gui Fa casually introduced the functions of the surrounding architecture.
"This is Zhu Jin's Taisokugū—the Palace of Embryonic Breathing, where breathwork is researched. Over there is my Shuitsukū—the Palace of Guarding the One, where meditation is practiced."
They journeyed onward together. Takatsuki voiced no desire to inspect the interiors of these palaces, and Gui Fa made no stops, continuing straight ahead.
"We have arrived... the Palace of Elixir Refining, Rien's quarters."
Rien had been the most obsessed with immortality among all the Tensen. Within her Palace of Elixir Refining lay countless records compiled over a thousand years—not only knowledge on refining Elixirs, but also the research findings of the other Tensen.
Now that its master was gone, Takatsuki didn't stand on ceremony, sweeping all the research materials straight into his Gate of Babylon.
Gui Fa watched Takatsuki store those fruits of labor into his vault without curiosity or attempt to stop him. He simply waited for Takatsuki to finish before continuing inward:
"The Tan Flowers are inside."