I’m grinding experience in the Cthulhu world.

[Golden Light Spell: 4638/10000; Level Zero] (Your vitality is robust, requiring only four hours of sleep each night to maintain your energy throughout the day.) With a sigh of relief, he exhaled deeply. After advancing to level three, the crafting of ordinary potions no longer contributed to his proficiency. Furthermore, his mastery of the Blood-Boiling Potion was hindered by the absence of certain materials, leading him to stockpile only basic potions and salves in recent days. He resolved to condense his herb crafting sessions to two hours each day, dedicating the remaining time to fervently practicing the Golden Light Spell. Since the spell could alleviate his strange condition, he aimed to advance it to the next tier. As a foundational skill within the golden wall, his anticipation grew. Given his current efficiency, he estimated that he could reach the next level in merely ten days. ... Eight Days Later, Night. Klaun sat cross-legged in his room, wholly engrossed in visualizing the Golden Light Spell. Four days prior, he had awoken to a severe sense of physical weakness. That day, his complexion was ashen, and his body trembled uncontrollably. Consequently, he abandoned herb crafting entirely, devoting all his time to the practice of the Golden Light Spell. With each onset of weakness, he found he needed to practice the spell for increasingly longer durations to recuperate. Fearing that two more such episodes could prove fatal, Klaun visualized his heart radiating golden light, akin to a sun casting brilliant rays throughout his chest and vital organs. He then gently moved the sun to his center, pausing briefly before envisioning it descending into his lower dantian. Finally, he imagined the myriad rays of golden light expanding, enveloping his entire being and emanating outward like a luminous sphere. As he completed his visualization, an enigmatic sensation surged within him, granting him knowledge of two talismans and two hand seals! Clear Heart Talisman: Pacifies the heart and conquers inner demons. Method: Draw the talisman, ignite it, and dissolve it in clear water for consumption. Golden Light Talisman: Radiates divine light to expel evil. Method: Affix the talisman to the chest, back, or onto objects to deter malevolent forces. Great Sun Seal: Position both thumbs opposing each other, interlace the remaining fingers tightly. Moonlight Seal: Cross the thumb and index finger, allowing the other fingers to remain naturally spread. The explanations of the talismans were straightforward, complete with illustrations detailing materials and drawing techniques. Klaun, however, did not dwell on the talisman creation; he urgently summoned the golden wall. As golden light flickered, the text pertaining to the Golden Light Spell transformed into a vibrant blue. [Golden Light Spell: 1/50000; Level One] (Calm the mind and purify the spirit, vanquishing malevolent entities. At the hour of the Rooster, worship the bright moon and bathe in its light, forming the Moonlight Seal while visualizing the serene moon cleansing your soul; at the hour of the Rabbit, face the rising sun, forming the Great Sun Seal while envisioning its illuminating warmth refining your being. Note: At this stage, you may only endure the lunar and solar essence during these two hours—do not be reckless!) Calm the mind and purify the spirit! The first tier of the Golden Light Spell is now intertwined with solar and lunar energies—excellent! Klaun felt a surge of joy; the recent shadows that had clouded his heart dissipated entirely. He suspected that the unforeseen physical ailments he experienced were remnants of the malevolent spirit's disturbances. The priest's two so-called holy rites had failed to eradicate the underlying threat, which was also a reason he hesitated to seek the priest's assistance. After all, seeking help again after failing to deliver on the initial promise would be foolish! That night, Klaun fell into a deep and peaceful slumber. ... As dawn approached, Klaun rose early, well before the sun had fully risen. After a hasty wash, he quickly boiled more than ten eggs. Once cooked, he placed the eggs into a paper bag, grabbed his firearm, and packed his water bottle and the bag into his backpack, heading east toward the town. He intended to stand on a hillside to greet the first rays of the rising sun. The night before, he had carefully contemplated the practice of the Golden Light Spell. According to the information provided by the golden wall, he understood that during the hours of the Rabbit and the Rooster, he would need to engage in separate visualization sessions. At the hour of the Rabbit, he would visualize his heart and body emanating radiant light under the morning sun while forming the Great Sun Seal. During the hour of the Rooster, he would only visualize the tranquil moonlight enveloping his entire being. At present, he could only utilize the solar and lunar energies to refine himself and was wholly incapable of harnessing their essences. Given his fragile state, he must avoid visualizing under the sun or moonlight during other hours. After nearly an hour of walking, Klaun finally arrived at his intended destination. Although the sun had yet to rise, the horizon was adorned with clouds that resembled golden cotton. He kicked aside pebbles and twigs, settling onto the ground. Facing the direction of the rising sun, he formed the Golden Light Seal and began his visualization. After more than ten minutes, as he envisioned the sun radiating golden light from his lower dantian, the sun finally broke over the horizon, bathing him in its warmth. Instantly, he felt an unfamiliar warmth enveloping him, and a translucent crystal sphere appeared in his consciousness. The sphere floated silently, not disturbing his visualization in the slightest. From this vantage point, Klaun "saw" a serpentine division line within the crystal sphere, with a hint of gold appearing at the left bottom side. As he prepared to examine it closely, an abrupt shock occurred. A terrified, frenzied scream resonated in his mind, carrying with it an inexplicable sense of decay. Klaun was instantly jolted from his meditative state, feeling as though someone was relentlessly pounding a gong near his head, causing his skull to throb. With widened eyes, he saw his arms revealing bulging blue veins. The veins twisted and coiled like a centipede, while beneath his skin, lumps appeared as if a group of mice were scurrying under a bedsheet. As the capillaries burst, his skin transformed into a blooming sea of crimson. Simultaneously, where the blood splattered, dark spots emerged, accompanied by a stinging sensation. Unbeknownst to him, similar phenomena were occurring across his entire face and body. Something was residing within him! A chill coursed from his head to his toes. He clenched his fists and gritted his teeth, enduring the agony. After what felt like an eternity, the aberration gradually subsided, though the black spots remained. Raising his hands, Klaun observed the spots with a sense of weariness. They resembled the gazes directed at those nearing the end of their days, an overwhelming essence of decay washed over him. After catching his breath for a moment, Klaun slowly stood up. He had an intuition that the malevolent spirit responsible for the recent murders in the town was currently residing within him. Though he did not fully understand the basis of this conclusion, he felt an unwavering certainty. With this realization, a tremor coursed through his limbs. Yet, there was still a way forward; at least the Golden Light Spell could restrain it. With that thought, Klaun exhaled deeply. He opened his backpack and retrieved the paper bag and water bottle. After taking a sip, he began to peel and consume the eggs. Once he finished eating the eggs and drank half a bottle of water, he rested for a while, feeling a slight restoration of energy. He shouldered his backpack and set off toward the town. Daylight had fully arrived, and the streets were beginning to fill with pedestrians. He could no longer afford to remain in this location for meditation. Aside from the increasing noise, should he encounter the earlier situation again, it might raise suspicions that he was possessed by a malevolent spirit. Given his current state, it was undeniable that he had indeed been afflicted! Entering his bedroom, he drew back the thick curtains, allowing the moonlight to flood the room. Klauen sat cross-legged, forming the Moonlight seal with his hands resting on his knees, and closed his eyes. He envisioned a silver full moon rising before him, casting its tranquil light over his body for a moment before the silver moon descended into his forehead. Just as he completed this step, a sudden icy sensation surged in his mind. Before Klauen could marvel at the immediate clarity the moonlight brought, this chilling feeling erupted, swiftly spreading throughout his body. He sensed something invading him, encasing his consciousness in a thin veil. His body involuntarily stood up, and in a state of panic, he found himself standing in front of the dressing mirror. The moonlight illuminated his figure, and Klauen beheld his own eyes transformed into golden vertical pupils, a dark tendril of flesh shooting forth from his face. The reflection in the mirror grinned eerily, revealing a set of pristine white teeth. Then he watched as his right hand slowly raised, the index and middle fingers curling in towards his face. Klauen suddenly realized that the creature controlling his body intended for him to gouge out his own eyes. In a surge of terror, his mental fortitude sharpened. The membrane surrounding his consciousness seemed to tear, and Klauen felt himself regain some control over his body. Specifically, he reclaimed partial control over the left side of his body. With a mighty effort, he seized his right hand just as it was about to reach his eye, pushing it away with all his strength while trying to tilt his head backward. An unsettling scene unfolded in the room: a man stood before the mirror, his right hand attempting to reach for his face, while his left hand pushed back with all its might. This was a battle of wills—winner takes all, loser is finished. Klauen didn’t know how he managed to hold on, but when a distant rooster crowed, the sensation of his body being controlled by a foreign entity receded like a tide. His body collapsed to the ground, convulsing, his mouth agape as he gasped for air. In that moment, he had never before appreciated the simple joy of being able to breathe freely. He felt utterly drained, both physically and mentally. Summoning his remaining strength, Klauen resisted the urge to sleep. Once the spasms subsided somewhat, he struggled to rise. He fetched a basin of water and doused himself. While drawing water, Klauen caught sight of his reflection, his complexion darkened, dotted with numerous coin-sized black spots. The cold shower was invigorating; he gathered his thoughts, ate a generous serving of cold rice and scrambled eggs, then began visualizing the Golden Light Incantation once more. The creature could manifest at night; if it returned tonight, he doubted he would be able to withstand it. Thus, he needed to utilize the daylight to its fullest, engaging in prolonged sessions of the Golden Light Incantation to weaken his enemy.