When it comes to cultivating immortality, it naturally starts with upgrading the herb garden.

Five days later, at No. 17 South Alley.

A hidden, barely perceptible flame shot into the sky, its tip slightly pointed, its base steady, and its center crimson.

"Introduction to Earth Fire Finger Technique!"

Song Chen's lips curled up as he looked at the firelight in front of him.

Now, the Earth Fire Finger in his hands can be used as a powerful killing move, which can be launched unexpectedly and instantly, with immense power.

However, there are also drawbacks. With the current reserves of spiritual liquid in the dantian, the Earth Fire Finger can only be released fifteen times, and the distance is short, only ten meters. If you really want to use it, you have to close the distance.

However, these drawbacks will disappear as your cultivation level and proficiency in spells increase, so there is no need to worry too much.

"Let's conclude today's spell practice!"

Song Chen picked up his hoe and began tending to the medicinal herb field again.

Over the past few days, the medicinal field has yielded a great deal, producing sixty spiritual herbs in just five days.

These medicinal herbs were naturally all taken, without exception.

As the production of spiritual herbs increased, Song Chen also discovered the drawbacks of the spiritual fields.

That means it cannot produce high-quality spiritual herbs.

Feng Sancai has many elixir recipes in his memory, and the spiritual herbs required have certain age requirements.

For example, the herb Tongmai needs to be aged for over a hundred years in many prescriptions; simply having one year's worth is far from enough.

Song Chen also had a solution for this situation: to increase the quantity to achieve the same medicinal effect.

But this is ultimately only a temporary solution and not a cure.

Song Chen sighed, "If only there were 'ripening rooms' in the later buildings."

"The 20% increase in single-herb fields and the accelerated growth from fertilizer rooms are simply insufficient to support the production of high-yield medicinal herbs."

Mentioning the fertilizer room, Song Chen also summoned a panel, and a virtual interface appeared before his eyes.

In the morning, Song Chen went to Fatty Dong's place again and successfully obtained the ribs of a peak Qi Refining cultivator and the essence blood of a late Qi Refining cultivator, among other goods.

Incidentally, I also bought the essence blood of a Qi Refining Peak cultivator for 3,000 taels of silver and 45,000 spirit stones.

Fifteen spirit stones per tael, a reasonable price.

At this point, all the upgrade materials for the Level 3 fertilizer room have been gathered.

Route 4

[Fertilizer Room lv1]

[lv2: Function: Self-gathering spirit for one hour daily, producing a moderate amount of biogas daily, increasing composting speed by 20%, and increasing the transformation of fertilized herbs by 20%]

[Upgrade Requirements: 100 spirit stones, a rib from a peak Qi Refining cultivator, 10 Qi Boosting Pills, 10 Qi Gathering Pills, 5 Mystic Ice Stones (Completed)]

"From now on, we won't have to worry about biogas and other resources."

Song Chen's thoughts shifted slightly, and the panel changed.

The fertilizer room was subsequently upgraded to level 3.

"Daily self-collection of spiritual energy should amplify the effects of fertilizer to some extent."

Just as Song Chen was pondering this, a cloud of green biogas floated in the air above the fertilizer room.

Song Chen was overjoyed; this amount of marsh gas alone could earn him at least fifteen spirit stones.

Although he doesn't lack spirit stones now, he still can't help but start calculating.

He then immediately found a pre-prepared gas storage bag, put the biogas into it, and set aside another storage bag specifically for storing it.

Song Chen took the ladle and poured the newly produced fertilizer into his dantian, his gaze returning to the virtual screen.

The conditions for fertilizer room level 3 also popped up.

[Fertilizer Room lv3]

【Route 1】

[lv3: Function: Produces one drop of superior spiritual liquid daily, produces a large amount of biogas daily, increases composting speed by 30%, and increases the transformation speed of fertilized medicinal herbs by 30%]

[Upgrade Requirements: Foundation Establishment, a complete corpse of a Foundation Establishment cultivator, and ten strands of Yin Soul]

【Route Two】

[lv3: Function: Produces one drop of top-grade spiritual liquid daily, produces a moderate amount of biogas daily, increases composting speed by 30%, and increases the transformation speed of fertilized medicinal herbs by 30%]

[Upgrade Requirements: Foundation Establishment, one complete corpse of a Foundation Establishment cultivator, ten Yin Soul Stones]

【Route 3】

[lv3: Function: Produces one drop of superior spirit liquid daily, increases composting speed by 40%, and increases the transformation speed of fertilized herbs by 50%]

[Upgrade Requirements: Foundation Establishment, a complete corpse of a Foundation Establishment cultivator, mastery of the 'Spirit Gathering Technique', and ten pieces of Yin Sand.]

Route 4

......

Song Chen glanced at them briefly and saw that they were all corpses of Foundation Establishment cultivators.

"It seems that once a building reaches level three, cultivation level becomes a mandatory requirement."

That's normal. If there were no cultivation level restrictions and Song Chen could keep leveling up, that would truly be defying the heavens.

"Based on the current situation, is it possible that the growth rate of the spiritual herbs could exceed 100?"

"If that's really the case, then medicines that take hundreds or thousands of years to develop may not be a pipe dream in the future."

Song Chen contemplated the future for a moment, then gathered his thoughts.

The most urgent task is to improve one's cultivation level. Instead of thinking, it's better to focus on improving one's cultivation level and researching elixirs.

A huge container filled with essence blood was taken out of the storage bag, and a massive amount of essence blood was poured into the wooden barrel.

As Song Chen stepped inside, a surge of rich spiritual energy instantly flooded his dantian.

In the past few days, he has not relaxed at all. Even without essence blood, he has persisted in cultivating with spirit gathering pills and mid-grade spirit stones.

Within five days, the spiritual energy in his dantian had condensed to ninety drops. This bucket of essence blood might very well help Song Chen return to the sixth level of Qi Refining.

Song Chen focused entirely on regulating his dantian, smoothly manipulating spiritual energy to continuously transform it into liquid.

Drop after drop of spiritual liquid condensed in his dantian...

Three hours later.

Song Chen's aura suddenly surged, his meridians solidified, and everything fell into place. His cultivation level returned to the sixth level of Qi Refining.

But he did not stop cultivating.

Instead, he took out a mid-grade spirit stone and a spirit-gathering pill to absorb the spiritual energy within. Only after the spiritual energy liquefied and stabilized did he breathe a sigh of relief.

"Blood Spirit Roots truly have no bottlenecks. As long as one continues to accumulate experience, breaking through to the Qi Refining Realm should be easy!"

Song Chen smiled slightly. With so many resources at his disposal, why would he have to worry about breaking through to the peak of Qi Refining?

"I just don't know if Foundation Establishment can continue to accumulate and break through to the next level."

Song Chen murmured something, got dressed, and headed towards the alchemy room.

A brown, long-tailed mouse scurried out of the wooden box, and in front of it was a quarter of a pill with cinnabar patterns, suspected to be of the fourth grade, and containing rich spiritual energy.

It glanced at Song Chen and pointed to the pills in front of it.

Song Chen nodded slightly and smiled, "Don't worry, there's no poison in it."

The pill-testing rat can neutralize most of the medicinal power of pills, turning it into nutrients that increase cultivation.

Unless the pill contains a large amount of erysipelas, one will not easily die from taking it.

Song Chen placed the quarter of the pill into the specially prepared medicinal liquid, and the pill dissolved instantly upon entering the liquid.

The test rat looked at the bowl of pills, nervously stepped forward and sniffed it. Before it could smell them, it was as if it had been electrocuted and swallowed them whole.

Then, Song Chen's eyes sharpened, and he used the 'X-ray vision' technique he obtained from Feng Sancai's memories to clearly observe the situation in the mouse's dantian.

Before long, a surge of spiritual energy far exceeding that of an equivalent amount of Spirit Gathering Pill welled up in the mouse's dantian, making the mouse squint its eyes in comfort.

Song Chen's eyes lit up, his gaze never leaving the mouse.

After observing the mouse for another hour to ensure that there were no other abnormalities besides the significant increase in its cultivation level, they were temporarily relieved.

Song Chen still did not take the pill himself. The mouse's condition could only ensure that the pill was fine for a short period of time, but could not guarantee that there would be no problems later.

He plans to observe for another week, and if there are no abnormalities, he will start mass production for his own consumption.

"As expected, it is likely a pill with potent spiritual energy."

Song Chen chuckled inwardly.

He didn't stop there; he recalled several pills that could be refined at present, trying to exchange them for more potent pills.

This process is always accompanied by intense anticipation; who knows what kind of miraculous elixir might be created!

For example, the current Grade 3 Heavenly Water Pill and Earth Fire Pill are very much worth looking forward to.

Both types of pills, taken separately, are excellent pills suitable for cultivators with water-type and fire-type spiritual roots.

I wonder if, after the pill is placed, it can be transformed into a pill with strong spiritual energy, just like the Crimson Qi Pill and the Cold Qi Pill?

Life went on in an orderly fashion.

Aside from cultivation, Song Chen devoted himself to alchemy, and his cultivation level steadily improved.

He calculated the increase in the spiritual liquid's value and concluded that it would take another six months to break through to the seventh level of Qi Refining, and that he would need to have abundant essence and blood.

Even so, it's still far better than before when I couldn't accumulate spiritual energy.

Two days later.

The selection process for the Lower Sword Sect has begun.