After placing the External Spirit Bone: Demon Willow Fluff onto a patch of Fire Ganoderma, Ye Yu activated the Spirit Bone Ability: Devouring Parasitism.
Very quickly, the Demon Willow Fluff completely devoured the life force and Spirit Power from that entire patch of Fire Ganoderma.
On the Douluo Continent, medicinal herbs are technically also a kind of plant-type Spirit Beast, though they're much less likely to develop true sentience compared to ordinary plant-type Spirit Beasts.
Now, only three stalks of ten-thousand-year Fire Ganoderma remained.
Ye Yu had used just one Demon Willow Fluff to consume all the others.
Based on his estimation, that one Demon Willow Fluff now contained roughly 30,000 years' worth of accumulated Spirit Power.
He then took out three more Demon Willow Fluff.
During his recent cultivation, the main body of the External Spirit Bone: Demon Willow Fluff had undergone further evolution, significantly increasing its age, So, it could now produce another new Demon Willow Fluff external Soul Bone.
Afterward, Ye Yu continued flying across the summit of the mountain, landing at different areas where spirit herbs grew.
Among the more numerous spirit herbs—Sun Flowers, Scarlet Flame Flowers, and Flame Lotuses—Ye Yu carefully harvested the most potent ones. He also plucked and stored that suspiciously golden lily, which he suspected might be an Immortal Herb, placing it carefully into a jade box.
As for the rest, he allowed his Demon Willow Fluff to consume them all.
As a result, the Spirit Bones stored inside the Demon Willow Fluff now each contained close to 30,000 years of Spirit Power.
Once everything was prepared, Ye Yu took flight once again and finally arrived at the Sun Fusang Tree.
In front of him, the massive golden tree was still tightly coiled by several Blue Silver Wood Dragons, each one digging their crystal-blue fangs deep into the Sun Fusang Tree's body.
At the same time, many delicate Blue Silver Jade Trees were growing from its surface—remnants of Ye Yu's Devouring Parasitism.
Fortunately, Ye Yu had maintained control over those parasitic trees, preventing them from continuing to absorb the Sun Fusang Tree's life force and Spirit Power unchecked.
Otherwise, the Sun Fusang Tree would've long since perished!
"It should work..."
Holding four strands of Demon Willow Fluff in his hands, Ye Yu muttered to himself with anticipation.
He gently pressed the four strands into the Sun Fusang Tree's body and activated Devouring Parasitism.
As the Demon Willow Fluff embedded into the tree, Ye Yu began releasing the Spirit Power accumulated from the Fire Ganoderma, Sunflowers, Scarlet Flame Flowers, and Flame Lotuses—essentially medicinal energy—into the Sun Fusang Tree's body.
He intended for the tree to absorb and refine it.
In Ye Yu's opinion, this shouldn't pose any problem.
Even if it's a plant-type Spirit Beast—who says plant-type Spirit Beasts can't absorb medicinal herbs?
He recalled that in the original series, in Soul Land II, a fierce plant-type Spirit Beast known as the Myriad Demon King, originally a Demonic Eyed Evil Tree, had become a savage beast precisely by consuming an Immortal Herb that grew nearby.
And the Sun Fusang Tree's "bloodline" was clearly superior to that of the Demonic Eyed Evil Tree.
If that tree could evolve through medicinal absorption, then the Sun Fusang Tree definitely could too.
As the Blue Silver Wood Dragons held the tree in place, and its Spirit Power and vitality had been nearly completely drained, the Sun Fusang Tree was already on the verge of collapse.
Any further parasitism would start consuming its source life force.
Sensing the pure Fire- and Light-attributed Spirit Power and life force being released inside it by the Demon Willow Fluff, the Sun Fusang Tree immediately began frenziedly absorbing and refining it.
Ye Yu could clearly feel the changes—its injuries were healing, and its Spirit Power was rapidly recovering.
As a divine-grade plant-type Spirit Beast nearing 100,000 years of cultivation, the Sun Fusang Tree possessed considerable intelligence.
Sensing that it was still no match for Ye Yu, it didn't resist, and instead continued absorbing the energy released by the Demon Willow Fluff to rapidly boost its cultivation and grow larger.
"As expected, even plant-type Spirit Beasts can absorb 'medicine.'"
Seeing that the Sun Fusang Tree's cultivation was rising rapidly, Ye Yu smiled in satisfaction.
He didn't stop it.
After all, the four Demon Willow Fluff strands were already parasitically embedded within the Sun Fusang Tree.
Even if it really did break through to 100,000 years, there was no way it could escape Ye Yu's control.
Sure enough, under the constant infusion of pure Fire and Light attribute, the Sun Fusang Tree's cultivation soon skyrocketed to the 100,000-year threshold.
But just as it broke through, the Sun Fusang Tree suddenly lashed out, trying to tear itself free from the Blue Silver Wood Dragons and attack Ye Yu.
Ye Yu merely sneered.
With a flick of his mind, he activated the four Demon Willow Fluff clones inside the tree—immediately triggering them to rampantly devour its Spirit Power and life force.
With four Demon Willow Fluff wreaking havoc inside its body, the Sun Fusang Tree couldn't even release a single Spirit Ability, let alone break free from the Blue Silver Wood Dragons to attack Ye Yu.
"Since the experiment is over... it's time to wrap this up."
A cold smirk curved on Ye Yu's lips.
He gave the command—and the four Demon Willow Fluff began draining everything: all of the Sun Fusang Tree's Spirit Power, all of its life force.
Soon, it was completely drained.
Its golden trunk, branches, and leaves faded to a dull yellow. The foliage wilted and dropped, the bark dried and cracked.
But just like with the Phoenix Perching Tree, Ye Yu paused.
He decided—not to kill the Sun Fusang Tree outright.
From previous experience with the Dark Devilgod Tiger, Ye Yu knew that when Spirit Power and life force are completely consumed, the formation of a Spirit Ring or Spirit Bone is interrupted.
This proved that energy conservation truly is a fundamental law of nature.
If he drained the Sun Fusang Tree to death, it would have no power left to form either a Spirit Ring or Spirit Bone.
So, instead, he chose to leave behind a single living root—a sliver of life.
That way, the Sun Fusang Tree could regrow in the future.
That was the ideal outcome.
Ye Yu dug out the surviving root and transplanted it into the Blue Silver Realm.
At the same time, he split off several Blue Silver Jade Trees from the mountaintop and planted them around the newly transplanted Sun Fusang Tree.
This way, within the Ice and Fire Yin Yang Well, it would enjoy the rich ambient energy of the spiritual zone while also basking in abundant sunlight every day.
"Let's go."
Retrieving the four Demon Willow Fluff strands from the withered Sun Fusang Tree, Ye Yu turned and prepared to leave.
He had already harvested every spirit herb above 10,000 years on this mountain.
With that, Ye Yu took Zhu Zhuqing and Xiao Wu, and left the mountaintop—heading deeper into the core zone of the Star Dou Great Forest.
This time, in addition to the Sun Fusang Tree, Ye Yu also aimed to hunt three powerful Spirit Beasts—one each with space, lightning, and spiritual attributes.