Ling Pengyun made a swift decision. Forming hand seals with both hands, he cast the Water Avoidance Technique, raising a thin blue light screen around himself.
The light screen served to isolate the water currents. When cultivators ventured deep underwater, they could channel spiritual power to propel the screen, carrying those within through the water.
Ling Pengyun hurried into the lake's shallows and continued until he reached the deep waters. Only then did he dive beneath the surface, following the aura of the Black Iron Flying Sword he had deliberately left embedded in the Azure Scale Water Python's head and flesh, pursuing the Azure Scale Water Python that had fled beyond sight.
The Azure Scale Water Python was indeed skilled in water. After merely a dozen breaths of pursuit underwater, Ling Pengyun lost the Black Iron Flying Sword's aura.
This could only mean that the Black Iron Flying Sword was extremely far from him.
Ling Pengyun immediately became vigilant. He took out a Water Shield Talisman and gripped it tightly, lest the Azure Scale Water Python, having shaken free of the Black Iron Sword lodged in its brain, return to launch a sneak attack on him.
Fortunately, that did not happen. Following the spot where the Black Iron Sword's aura had last vanished, Ling Pengyun arrived at the lakebed in the central region of Azure Stone Lake, beside a deep, several-foot-wide cavern.
The cavern was bottomless, yet Ling Pengyun could sense that it continuously poured water into Azure Stone Lake.
"This deep cavern should be the Underground River that maintains the water level of Azure Stone Lake!"
"And the Azure Scale Water Python's origins were likely just as I suspected—it arrived in Azure Stone Lake through this Underground River sometime recently!" Ling Pengyun guessed.
"There is an eighty or ninety percent chance that the heavily wounded Demon Serpent escaped through this Underground River, where the aura of my Black Iron Sword last disappeared!"
After hesitating for only a moment, he headed upstream, against the current of the Underground River.
Traveling against the current consumed a great deal of spiritual power.
After advancing only one li through the enormous Underground River, Ling Pengyun had already expended nearly a tenth of his spiritual power.
I still have seventy percent of my spiritual power left. If I travel another three li without catching up to the Azure Scale Water Python, I must turn back. Otherwise, if my spiritual power is exhausted and the whereabouts of that Azure Scale Giant Python are discovered, it may ambush me from the shadows! Ling Pengyun thought to himself.
After he traveled another half li, the Black Iron Sword's aura appeared once more.
This meant that the Azure Scale Water Python was nearby!
He restrained his aura and slowed his pace against the Underground River's current, silently approaching the source of the Black Iron Sword's aura ahead.
Ten breaths later, Ling Pengyun had drawn within fifty zhang of the Black Iron Sword, yet he saw neither the sword nor any trace of the Azure Scale Water Python.
After searching for quite some time, Ling Pengyun finally realized that the Black Iron Flying Sword's aura was coming from within a cliff wall in the Underground River.
He searched for a long while before finding a one-foot-wide deep hole near the cliff wall from which the Black Iron Sword's aura emanated.
"Blood scent?" From several zhang away from that foot-long deep hole, Ling Pengyun could already smell a thick bloody scent.
There was no need to guess. Ling Pengyun understood that this passage leading to the Black Iron Sword was, in all likelihood, the hiding place of that heavily wounded Demon Serpent.
"Eh, spiritual qi?" As Ling Pengyun approached the entrance to the nest, he also sensed a faint trace of spiritual qi drifting out from within.
"Could there be spiritual treasures inside? Or perhaps a spirit vein?"
The moment this thought arose, Ling Pengyun's eyes lit up.
Back when he was young and still learning about the Cultivation World at the Clan School, his elders had emphasized that demon beast nests often contained spiritual treasures.
They might be spiritual materials left behind from demon beasts that had been eaten clean, spiritual plants, several pieces of Spirit Iron Ore found by demon beasts, a cultivator's Storage Bag, and so on. All of these might be discovered within a demon beast's nest.
As for his speculation about a spirit vein, it stemmed from the spiritual qi flowing from the nest entrance.
Whether that spiritual qi came from spiritual treasures or a spirit vein, however, could only be determined by entering the place.
Now that he had found the Azure Scale Water Python's trail, he did not hesitate any longer. He directly activated the Water Shield Talisman in his hand, conjuring a Water Shield that floated around his body.
Then he formed hand seals and cast the Water Shield Technique, placing another Water Shield around himself.
With two Water Shields protecting him, Ling Pengyun felt much more at ease.
Ling Pengyun naturally had no intention of entering the demon serpent's nest through such a narrow entrance, where combat would be difficult.
With a wave of his hand, he fired a Water Thorn into the nest entrance at the bottom of the Underground River.
A dull sound of stone being struck rang out.
Immediately afterward came the hiss of a serpent.
Delight appeared on Ling Pengyun's face, and he thought, It really is in this foot-long cave!
At that same moment, he sensed the Black Iron Sword's aura moving, slowly drawing closer to him.
"It really is here."
He retreated several steps, widening the distance between himself and the nest entrance at the bottom of the Underground River. Forming hand seals, he condensed three Water Thorns and one Water Arrow that hovered beside him, waiting for the Azure Scale Water Python to burst from the cave.
Before long, the Azure Scale Giant Python, its body marked by three enormous wounds, shot furiously out of the nest entrance. Twisting its body, it charged at Ling Pengyun in boundless rage.
Ling Pengyun sent the three inch-long Water Thorns and the three-inch-long Water Arrow he had prepared crashing toward the charging Azure Scale Water Python.
After launching his attacks, Ling Pengyun formed hand seals and recalled the Black Iron Sword buried deep in the Azure Scale Water Python's head and flesh.
He infused it with a spell seal containing a tenth of his spiritual power, causing the Black Iron Sword's spiritual glow to flare forth. He sent it flying out once more, attacking the Azure Scale Water Python alongside the spells he had cast.
The Azure Scale Water Python was ultimately only a Qi Training Stage demon beast, somewhat stronger than a wild beast, and possessed little intelligence. Before bursting out of its nest, it had not cast a Water Shield in advance.
For a moment, its massive body was like a target, struck one after another by the three Water Thorns, the Water Arrow, and the Black Iron Sword launched by Ling Pengyun.
Bloody blossoms burst from its body, dyeing a wide swath of the surrounding water red.
It hissed continuously in pain, its hatred for Ling Pengyun intensifying further. Ignoring its wounds, it gritted its teeth and continued charging at Ling Pengyun, intent on crushing him to death with its thick, powerful body.
But Ling Pengyun had long been prepared. With a wave of his hand, he placed the two Water Shields floating nearby in front of him. His hands formed seals once more, and in the blink of an eye, he summoned a Water Thorn that pierced through the demon serpent's sturdy scales and plunged into its flesh.
Ten breaths later, before the Azure Scale Water Python could break through the two Water Shields, it died beneath the bombardment of more than ten Water Thorns from Ling Pengyun. Its snake head was riddled with holes pierced through by Water Thorns.
In this battle, the Water Thorn Technique, which he had cultivated to the perfected realm and could cast in an instant, had rendered immense service. It further strengthened Ling Pengyun's resolve to comprehend spells.
He glanced at the Azure Scale Water Python, which had sunk to the bottom of the Underground River. Its body was already mangled beyond recognition, with scarcely any intact parts left, and he inwardly lamented.
"With this Azure Scale Water Python's snakeskin and scales damaged to such a state, my earlier wish of commissioning a Weapon Refiner to forge a First Rank Middle Grade Water Attribute Daoist Robe from this demon serpent's skin and scales appears to be gone!"
With a soft sigh, Ling Pengyun turned his gaze toward the nest entrance not far from the Azure Scale Giant Python's corpse.