It was a valley with a radius of hundreds of zhang, shrouded in a layer of white flames on all sides, and the scorching aura emanated, making Lei Yu's heart feel a trace of palpitations.

"What kind of flame is this?"

Lei Yu's heart was awe-inspiring, the white flames were completely different from the surrounding red flames, as if he was a master outside the world, and the white flames were separated, allowing the crimson flames to flow endlessly, but he himself did not move.

The valley is surrounded by mountains, and the white flames are leaping, and it is impossible to see what is really going on in the valley. It's just that Lei Yu can feel a terrifying amount of power, this force is like an abyss and the sea, unfathomable, and he can't resist it with his current strength.

It's a forbidden power, terrifyingly boundless, as if it can burn everything out.

Lei Yu gradually approached this valley, the scorching breath surged, his face was shrouded in a white light, there was white smoke coming out of his skin, the water in his body was constantly evaporating, even his blood seemed to be a little unbearable, and began to boil uncontrollably.

"No, if it goes on like this, I won't be able to support it!"

After advancing for a distance of dozens of zhang, Lei Yu finally decided to retreat, this white flame was too powerful, and it seemed to contain a trace of the breath of fairy fire, which was not something that his level of strength could touch.

"Whew!"

Lei Yu gasped for breath and retreated dozens of feet away before stopping. His eyes looked at the valley shrouded in white flames, and his heart still palpitated.

This kind of flame can definitely destroy him, even if it is stained even a little, I am afraid it will cause him great damage.

"It seems that this is the source of this Heavenly Fire Domain, otherwise, it would be impossible for such a powerful flame to exist. ”

Lei Yu had a hint of realization in his heart, the existence of the Heavenly Fire Domain was also very strange in the Little Immortal Thunder Realm, and this was the only place where the source could be recorded.

When the Heavenly Fire descended, the earth cracked, and the infinite flames spread, and the Heavenly Fire Domain was born. Therefore, in this Heavenly Fire Domain, there must be a source. And now, Lei Yu has found its source.

Although the white flames covered everything in the valley, Lei Yu knew that there must be more powerful flames in the center of this valley, dozens of times more powerful than the white flames.

"Forget it, let's open a simple cave here for cultivation!"

Lei Yu made a decision, this is already the central area of the Heavenly Fire Domain, and the fire attribute thunder power is furious to the extreme, which is just right for cultivation.

Flying to a volcano that no longer erupted, Lei Yu casually slapped at the mountain, and in an instant, a roar came. Then, I saw a simple cave house appear on the mountainside.

Without much stopping, Lei Yu directly entered this simple cave mansion. Subsequently, he arranged a defensive formation at the entrance of the cave mansion, and he was about to enter the cave mansion for cultivation, the fire attribute thunder power here was too strong, and if he didn't cultivate, it would be a fee.

Lei Yu sat in the cave, running the "Five Elements Thunder Sutra", and a stream of extremely powerful fire attribute thunder poured into his body like a storm, and then entered the heavenly ** aperture, and began to squeeze Aoki Lei.

The heavenly ** aperture is getting hotter and hotter, as if there is a flame burning, but Lei Yu doesn't care about it, the "Five Elements Thunder Sutra", as the cultivation method of the five elements thunder, can naturally adjust the power of the five elements. When the fire attribute thunder power reaches a certain level, it can be fused with Aoki thunder qi and the power is doubled.

In this way, Lei Yu cultivated in this simple cave mansion, completely ignoring external movements. Time passed day by day, and in the blink of an eye, half a month passed.

At this moment, Lei Yu was still sitting in the cave, his body was covered with dust, and streams of red fire attribute thunder surrounded the cave, and all kinds of fire spirits were hovering in the sky, and the cave seemed to have become a flame world.

In this environment, Lei Yu's heavenly ** aperture has also changed, and the fire attribute thunder power is everywhere, and gradually the green trees formed by the green wood thunder have also been infected, and a layer of red flames has emerged on the green surface.

It's just that this layer of flame did not cause any harm to the green tree, on the contrary, the wood and fire are mutually beneficial, and the two coexist, and the green tree has a faint sign of growth, and the small tree that originally had only a few leaves actually grew a few more.

Moreover, the newly grown leaves are not green like the previous leaves, but a dark green, and even the veins on the leaves are flame-like, which is extremely strange.

"Boom!"

A loud noise came from outside the cave, as if the heavens were cracking, and the surrounding mountains trembled, and more magma erupted. Suddenly, the heavens and the earth were enveloped in flames, and the scorching aura reached a higher level.

"What's going on?"

Lei Yu, who was cultivating, was awakened, and the mountains trembled even more, as if some powerful thunder beast was putting pressure on the mountains, so that the entire mountain showed signs of collapsing, and it seemed that it could collapse at any time.

Lei Yu's face changed drastically, although he was deep in the cave, he could feel a beastly power that was extremely powerful, covering the heavens and the earth, making him can't help but be frightened.

"Roar!"

The roar of the thunder beast came, and this fire domain shook, and I don't know how many volcanoes collapsed in the road, which can be called a roar that shook the mountains and rivers.

"You can't stay here any longer, or sooner or later, it will collapse!"

Although he didn't know what the situation was outside the road, Lei Yu knew that he couldn't stay here for long.

He turned into a streamer and rushed out of the cave, and a scorching qi rushed towards him, making him can't help but retreat dozens of feet.

This qi was extremely hot, scorching everything, making Lei Yu's skin dry and cracked, and a trace of scars appeared in his body, blood flowed out, staining his clothes red, looking extremely terrifying.

It's just that Lei Yu didn't care about the scars on his body, because he saw a more shocking scene. It was a huge white lion, hundreds of feet long, and its whole body was snow-white, like white satin, and it looked extremely smooth.

However, the feeling that this white lion brought to Lei Yu was extremely dangerous, because he could see that the white hair of this lion was not ordinary hair at all, but was composed of white flames. In other words, this was not an ordinary thunder beast, but a fire spirit.

A fire spirit formed by white flames, Lei Yu's heart shook wildly, he could feel the strength of this fire spirit, at least the cultivation of the Lei Dan stage, the horror was boundless, absolutely amazing.

Going upriver along the long river of flames, Lei Yu saw too many fire spirits, but most of these fire spirits were cultivated in the Thunder Qi and Thunder Gang periods, and none of them were in the Thunder Dan period. Now, he had seen a real Lei Dan Fire Spirit here, and this didn't shock him.

Fire spirits, spirits in fire, are too difficult to form, like ordinary mortal fires to form fire spirits, I am afraid it will take hundreds of thousands, millions of years, or even tens of millions of years, and only in a place like the Heavenly Fire Domain can there be so many fire spirits.

However, even so, it is very difficult to give birth to a fire spirit that has been cultivated in the Lei Dan stage, and it is impossible without great chance.

The white lion in front of him was dozens of feet long, with thick limbs, and white flames leaping all over his body, like a giant beast in fire, constantly attacking the valley surrounded by white flames, trying to break through this barrier.

However, the white flame was extremely strong, and even though the white lion was impacted, it did not move, without the slightest sign of relaxation. Instead, streams of white flames poured out of the valley and burned towards the white lion, causing a lot of trouble for the white lion for a while.

"Roar!"

The white lion roared as if it was about to break the mountains and rivers, shaking the heavens and the earth. I saw that its hind limbs kicked the ground, and the momentum was amazing, and it was about to launch a violent impact.

A white whirlwind set off, and the white lion turned into a white light and rushed straight towards the valley. A huge momentum poured out, and in the valley, white flames rolled up, like a monstrous giant Lang, and also rushed towards the white lion.

Two powerful forces collided together, and an earth-shattering explosion erupted, and the white light of this fire domain soared into the sky, sweeping hundreds of miles in a radius.

Volcanoes were blown by the fire wind like papier-mâché and turned to ashes. The crimson magma came out of the sky and sprinkled all over the heavens and the earth, like a splash of ink painting, which looked particularly weird. It's just that Lei Yu didn't dare to slack off, and the "Nine Netherworld Steps" were used, and he left the place as soon as possible, avoiding the aftermath of the white lion.

The white lion is too terrifying, even if it is just the aftermath, he can't bear it, he may be involved in it anytime and anywhere, and when the time comes, even if it is called heaven and earth, it will not be spiritual.

"Boom, boom!"

A violent collision sounded, and the white lion's onslaught ended in failure, but it did not have the slightest intention of giving up, but persevered, and continued to rush towards the valley, as if there was something in it that attracted it.

A quarter of an hour, half an hour, an hour...... The white lion showed no signs of stopping, and it slammed into the valley like a brute that had lost its mind, and the entire source of the long river of flames was almost reduced to ashes because of its impact.

Mountains shattered and turned to smoke, mountains turned plains, and infinite magma emerged from the abyss underground, covering everything and turning everything to soot.

At this time, Lei Yu also seemed to see something, there was definitely something in this valley that the white lion wanted. Otherwise, the white lion would not be so persistent, there must be some secret in it.