"If it really doesn’t work, I can only use the forbidden area."

Sunan gathered his thoughts and continued walking forward.

Thunder Stones mostly appear in areas densely hit by lightning strikes; it’s unlikely to find them on the outer edges of the Thunder Elemental Space. He must explore further within.

But he hadn’t walked far before encountering a Thunder Elemental Spirit.

Low-level Thunder Element Spirits look like clumps of lightning flickering with dense arcs.

Only as their power increases do Thunder Element Spirits gradually take on a human form.

When reaching the level of an Elemental Giant Spirit, they transform to have a humanoid upper body, with a mist-like appearance below, surrounded by electric arcs, or adopt a full human-shaped outline.

The spirit before him was just a low-level Thunder Elemental Spirit, without even a blurry humanoid outline, which Sunan easily obliterated with a casual Magic Missile.

There’s no lack of energy in the Thunder Elemental Plane.

Here, the spiritual power expended casting spells can be quickly restored.

But there’s another more severe issue here.

That is, in the Thunder Elemental Plane, energy particles other than those of lightning almost don’t exist.

This means that nearly no spells requiring other types of energy particles can be cast here.

Given that Thunder Series spells are nearly ineffective against Thunder Elemental Spirits, Sunan’s combat options here are limited to non-elemental spells like Magic Missiles, Rings of Calamity, Engraving Gemstones, and liquid metal.

As for Black Thunder, it serves little purpose in the Thunder Elemental Plane.

After the Thunder Elemental Spirit died, it left behind some crystal powder.

This is Elemental Crystal Dust, a material rich in elemental energy that can be used for enchantment or crafting magical items.

Sunan beckoned with his hand, collecting it into his Space Ring.

In the half-plane filled with thunder elements, Sunan’s distinct aura stood out.

Even from afar, Thunder Elemental Spirits could sense his presence.

Along the way, most Thunder Elemental Spirits snapped and crackled as they charged toward him, angrily trying to turn him to charcoal.

Only a few drifted lazily in mid-air, floating like clouds, not even glancing at him.

Sunan didn’t provoke those leisurely Thunder Elemental Spirits, only dealing with the aggressive ones.

The deeper he ventured, the thicker the air with tangible lightning elements, even forming substantial arcs flickering in the void.

The Thunder Elemental Spirits encountered became increasingly formidable.

Sunan promptly released two Secret Puppets.

Ordinary puppets can’t harm the ethereal Thunder Elemental Spirits; only high-level puppets, processed with constant magic and demonization, could contend with them.

With the Secret Puppets clearing the Thunder Elemental Spirits, Sunan finally freed up his energy to focus on finding Thunder Stones.

Soon, he made a discovery.

With a gesture, a pitch-black stone by the roadside suddenly rose and landed in Sunan’s palm.

Feeling the violent thunder energy within the stone, a hint of a smile appeared on his face.

Finally, he had a gain!

Sunan then thoroughly searched the surrounding area and indeed found many Thunder Stones.

With the harvest, Sunan grew more motivated.

There’s no day and night in the Thunder Elemental Plane; due to its vast dimensions, encountering other creatures is rare, making it easy to lose track of time.

Not knowing how much time had passed, when Sunan finally stopped, his Space Ring already contained more than two hundred Thunder Stones.

"These many Thunder Stones are enough to craft three pieces of Black Thunder."

Sunan smiled slightly, glancing at the two Secret Puppets by his side.

Despite enduring multiple battles, the Secret Puppets barely sustained any injuries.

After all, their opponents were just a group of Elemental Spirits.

Having defeated numerous Elemental Spirits, his Space Ring also accumulated a considerable amount of Elemental Crystal Dust.

"Compared to Elemental Crystal Cores, Elemental Crystal Dust is less valuable."

Just a while ago, Sunan had spotted an Elemental Giant Spirit from afar.

However, he didn’t plan to fight on the Giant Spirit’s home ground, so he avoided early, ensuring it didn’t notice him.

"Speaking of which, Elemental Giant Spirits are also a kind of divine creature."

In energy-rich and pure elemental planes, natural divinity easily arises, making Elemental Spirits the most likely species to birth divine creatures.

For instance, Elemental Giant Spirits, Giant Spirit Elders, and Elemental Lords are all divine creatures.

The rules they wield are often tied to their elemental attributes.

In other words, divine energy might be extractable from Elemental Giant Spirits.

But considering the difficulty of killing a Thunder Elemental Giant Spirit in the Thunder Elemental Plane, Sunan abandoned the thought.

In their home ground, the Thunder Elemental Giant Spirit’s combat strength could increase by half, which was relatively modest, while his power was heavily restricted by the environment—exchanges like this were too risky.

Perhaps he could try when his power rises further, but for now, it’s akin to courting death.

Sunan shook his head, opened a spatial passage, and returned to the Dragon Remains Tower.

In the subsequent time, Sunan immersed himself in crafting Black Thunder and refining the Demon Pattern Core.

The former took less than two months to complete, adding three pieces of Black Thunder to Sunan’s collection. 𝙛𝓻𝒆𝓮𝒘𝙚𝙗𝒏𝙤𝙫𝓮𝒍.𝓬𝒐𝙢

The latter took nearly two years of intermittent research before succeeding.

The refined Demon Pattern Core can be activated via arrays set within Secret Puppets, requiring only the infusion of energy particles.