There is a 100% explosion rate at the beginning of the mythical world!

"It's the legendary ancient thunder dragon!"

"What? Ancient thunder dragon!"

"Could it be the legendary ancient thunder dragon that can control thunder!"

"It's incredible that we can still see the ancient thunder dragon now!"

The emperors looked at Xiao Hei in amazement.

A glimmer flashed in the eyes of Emperor Xuanyuan Huangdi. No wonder Sun Dasheng valued it so much!

It can evolve into an ancient thunder dragon now, and its potential in the future is immeasurable!

"It's been so many years, and it's hard to find a dragon, let alone an ancient thunder dragon that exists in the legend!" Yandi Shennong said with emotion.

Xuanyuan Huangdi looked at Chu Bei and smiled: "Young man, you are really amazing. You have found such a spiritual pet!"

Seeing that the emperors were so optimistic about Xiao Hei's evolution into an ancient thunder dragon, Chu Bei was naturally even more delighted.

The ancient thunder dragon is also an extremely powerful existence in Chinese legends, and its ability to control thunder and lightning is unmatched!

"Boom boom!"

The thunder of the dragon horn washed over Xiao Hei's body like a waterfall. The dark dragon scales on Xiao Hei's body became brighter and brighter. The whole dragon body was surrounded by thunder and lightning, crackling.

"Ah!"

Xiao Hei's body shrank to a hundred meters in an instant, and a thunder and lightning shot out from his body and hit a mountain next to him.

"Boom!"

With a loud bang, the thunder and lightning directly collapsed the mountain.

"So powerful!" Emperor Xuanyuan couldn't help but sigh.

The thunder and lightning shot out from the body were so powerful!

The others stared with their eyes wide open.

"If this is used with thunder and lightning magic, what will happen?" Taihao murmured.

The Bull Demon King exclaimed: "My dear, if it grows up, I'm afraid the Dragon King of the East China Sea will have to stand aside!"

Suddenly, the world changed, the sky was covered with dark clouds, and the wind was blowing!

"Ding, your pet Xiao Hei has set off the heavenly tribulation, please be prepared!"

Chu Bei was stunned when he heard the system upgrade. The heavenly tribulation was triggered just after the evolution was completed?

When Xiao Zi evolved, he needed to improve his strength to trigger the heavenly tribulation, but now Xiao Hei has triggered the heavenly tribulation just after his evolution. To what extent has his strength increased?

The sky was filled with dark clouds, and the strong wind almost overturned the trees.

Lightning flashed in the thick dark clouds, and thunder roared with great momentum.

"The heavenly tribulation is coming!" Emperor Xuanyuan said in a deep voice.

"This heavenly tribulation looks very powerful, even greater than the heavenly tribulation we have experienced before!" Emperor Yan Shennong exclaimed, and he vaguely felt the huge power contained in the tribulation cloud.

The dark clouds continued to expand until it was dark within a radius of ten miles.

Chu Bei also clearly felt that this heavenly tribulation was different from the last time Xiao Zi encountered it.

"Boom!"

Suddenly, tribulation thunders of different colors flashed in the tribulation cloud!

After the seven colors of red, orange, yellow, green, blue, and purple, there were also gold and black!

"It is the nine-color heavenly tribulation!" The emperors exclaimed.

Even the Bull Demon King was stunned.

"It's actually a nine-color heavenly tribulation!" The Bull Demon King shouted.

"When I was going through the tribulation, it was only a seven-color heavenly tribulation, but it turned out to be a nine-color heavenly tribulation!"

Chu Bei was also a little surprised. Xiao Zi was a seven-color heavenly tribulation, but Xiao Hei is now a nine-color heavenly tribulation!

It is estimated that the higher the potential of the system, the stronger the heavenly tribulation that appears!

"I wonder if it can withstand the nine-color heavenly tribulation!" Shao Hao couldn't help but get a little nervous.

Chu Bei looked at Xiao Hei, and saw Xiao Hei wandering in the air, with lightning on his dragon body, looking up at the tribulation cloud.

"Boom!"

Suddenly a red lightning flashed out from the tribulation cloud and instantly struck Xiao Hei.

"Boom!"

An explosion sounded, and all the stones around Xiao Hei turned into powder!

"The tribulation has begun!"

"This first heavenly tribulation is so powerful!"

"This heavenly tribulation is too terrifying!"

The emperors were also shocked by this heavenly thunder.

Everyone looked at Xiao Hei in the smoke nervously, wondering what his situation was.

Until the smoke cleared, Xiao Hei actually happily circled in the air and flew into the sky!

"Boom!"

Another red sky thunder struck down, Xiao Hei opened his dragon mouth and swallowed the sky thunder into his stomach!

Then he shook his head with satisfaction, looking at the robbery cloud expectantly, as if waiting for the next sky thunder to fall.

"What?!"

The emperors were shocked.

"He is actually, actually swallowing the sky thunder!"

"It's unbelievable!"

"This is the first time I've seen a spirit beast swallowing sky thunder!"

"What is this situation!"

The emperors looked at Xiao Hei in the sky in astonishment, all of them were dumbfounded.

"Boom boom boom!"

The sky thunder continued to hit, and Xiao Hei opened his dragon mouth to swallow it, leaving no one behind.

As Xiao Hei swallowed the sky thunder, the lightning on his body became more and more dense, his pair of dragon horns were even more brilliant, and his dragon body became brighter and brighter!

"It seems to be swallowing and refining the sky thunder for its own use!" Xuanyuan Huangdi said in shock.

"Hiss!"

The emperors took a deep breath.

There is such a thing!

This is the thunder of heaven, and it is the legendary nine-color heavenly tribulation with great power, which is enough to destroy the world!

It actually devoured and refined it!

Is this the legendary power of the ancient thunder dragon?

It is highly immune to the thunder attribute, and it can also devour the thunder of heaven!

This is really abnormal!

The thunder of heaven poured down, bombarding one after another, and all were swallowed by Xiao Hei.

After ten minutes, all the seven-color thunder tribulation was swallowed by Xiao Hei, and the eighth thunder tribulation began.

Golden thunder tribulation!

A golden thunderbolt came down, but Xiao Hei met it and swallowed it in one gulp.

But the residual power of the golden thunderbolt was real, and it instantly pressed a huge pit on the ground left by Xiao Hei, and several mountaintops were blown into pieces!

The emperors were even more shocked to see that Xiao Hei could even swallow the golden thunderbolt.

"Once this dragon becomes a true dragon, its strength may have surpassed that of a true immortal, or even a celestial immortal!" Emperor Xuanyuan murmured.

Such thunderbolts, even ordinary celestial immortals would have to avoid them, but Xiao Hei swallowed them anyway!

After the golden thunderbolt is the last kind of thunderbolt, the black thunderbolt!

"Boom!"

The black thunderbolt cut through the sky, like a black dragon, and the space nearby was already distorted!

Xiao Hei's pair of dragon horns emitted black light, and a dragon shadow appeared above Xiao Hei's head.

The dragon shadow opened its huge mouth and swallowed the black thunderbolt as usual, but the aftermath of the thunderbolt had smashed a huge depression in the ground, as if it had been hit by a meteorite.

"Is this possible?!" The emperors were shocked.

"It is tempering its soul!" Emperor Xuanyuan glared and said in astonishment.

All nine black thunderbolts were swallowed by the dragon shadow, and the dragon shadow returned to Xiao Hei's body again.

Xiao Hei's body suddenly increased by a thousand meters, and the lightning on the dragon's body turned black!

The dragon scales on its body became brighter and brighter, and the dragon's might filled the world!

"This, this is the real dragon!" Emperor Yan Shennong murmured.

"And it is the dragon of the ancient thunder dragon!" Emperor Xuanyuan said.

The calamity clouds gradually dissipated, and soon the sky returned to its original blue appearance.

"Ah!"

Xiao Hei roared to the sky, and the dragon's roar shook the world!

"Ding, your pet Xiao Hei successfully passed the tribulation!"

"Ding, your pet Xiao Hei became the immortal beast Tai Gu Thunder Dragon!"

Chu Bei was overjoyed. Xiao Hei finally passed the tribulation successfully, became an immortal beast, and became a real dragon, the ancient thunder dragon!