Although the space within the ancient city is much larger than the outside world, it was created by a single Dou Saint so its size is limited.
In just half an incense stick of time, Xiao Yan flew to the dry river that divided the Yin-Yang sides of the city.
"If we go further, we will reach the dark side." Xiao Yan stopped and looked up at the Yin-Yang Evil Saint who was floating in the sky.
"I heard that no one who has been contaminated by the aura of this place has survived. They have all become machines that only know how to kill."
"Just go. Why don't you have the courage of the Xiao clan's heaven's pride?"
"If you have no brains but only courage, you are a fool."
"With my relationship with Shaobei, I will naturally protect you."
In the end, Xiao Yan still chose to enter this dark fog.
This fog made him feel irritable and give rise to violent killing intent. Its unknown what would happen if he were to be contaminated by it.
After entering the black fog, Xiao Yan felt that his eyes became dark and his field of vision shrank sharply.
"Use your soul power. With your seventh-grade intermediate soul power, you can still see here." The voice of Yin-Yang Evil Saint sounded from behind him.
Xiao Yan's body paused slightly before he released the majestic soul power.
Although his soul power was also hindered to a certain extent after getting into contact with the black fog, he could 'see' and sense the space within a hundred feet of him.
"Go forward along this road in front of you." The soul of Yin-Yang Evil Saint floated in the sky, it appeared that he was not afraid of the thick fog at all, he constantly pointed the way for Xiao Yan.
However, as his soul power gradually came into further contact with the thick black fog, Xiao Yan felt waves of violent and murderous emotions constantly infiltrating his soul.
Gradually, his eyes turned blood red.
"Good, since you can hold on until now, your soul power is very solid for rank seven, your will is also much stronger than I thought." Yin-Yang Evil Saint laughed.
"Don't make these jokes, I can't hold on any longer." Xiao Yan panted, the violent killing intent had already infiltrated his soul, gradually affecting his will.
He now had a growing desire to tear apart everything in front of him, an impulse to destroy everything.
Even he himself was not sure how long it would take for him to go crazy.
"No, if I don't leave now, I will be lost." Using the last bit of clarity he had left, Xiao Yan was ready to retreat.
"Don't retreat." The voice of Yin-Yang Evil Saint rang out, a clear light shot out from his soul and fell into Xiao Yan's body without being affected by the black fog.
The moment the clear light fell into Xiao Yan's body, his soul that had been soaked in the black fog was instantly cleansed, and the violent emotions in Xiao Yan's soul quickly subsided, an unprecedented clarity remained in him.
"My soul power has become purer." Xiao Yan showed a hint of joy on his face, but when his soul power sensed the Yin-Yang Evil Saint, he found that the other party's soul had faded a bit.
"Senior." Xiao Yan finally had a little respect for him.
"Haha, I'm a dead man. It's already part of my plan to use this little bit of remaining soul power to cultivate a successor. You don't have to thank me." The voice of Yin-Yang Evil Saint revealed a carefree attitude.
"Keep going forward; you are about to come into contact with a truly terrifying secret!" Yin-Yang Evil Saint's voice contained something.
"What secret can scare mm, the Xiao clan's Imperial Son? Could it be about some Dou Sovereign? I have even seen a living Dou Sovereign, not to mention a little Dou Sovereign's secret." Xiao Yan curled his lips and continued to move forward.
Every time he walked a certain distance, he would feel the violent killing intent spreading in his heart again, but every time he was about to give up, the Yin-Yang Evil Saint behind him would always bless him with a little light at the appropriate time.
After a few times, Xiao Yan felt that his soul power was becoming purer and purer. This was not a quantitative improvement, but a qualitative leap.
If he cultivated hard for a year or two, he would surely be able to break through to the seventh-grade advanced level.
As these clear lights were released, the soul body of Yin-Yang Evil Saint became a little more illusory.
Every stream of clear light that was used cleansed Xiao Yan's soul was his soul origin.
Finally, after passing through the endless black fog, a ray of light appeared in front of Xiao Yan.
In front of him, there was another identical Yin-Yang altar.
However, the scene in the altar made Xiao Yan's scalp numb.
In the Yin-Yang altar, a monster over two meters tall sat in the center of the altar.
The monster was covered with red hair, its limbs were swollen and bulging, and the black nails on its hands and feet were sharp. The face was hideous and terrifying, like a demon walking out of the abyss.
The weirdest thing was that his blood-red eyes were staring at him.
The moment he looked into these eyes, a chill rose from the depths of Xiao Yan's spine. Through these eyes, he seemed to see endless ferocity and ominousness.
The next moment, red hair grew out of his body.
"Roar!" Xiao Yan let out a low roar from his throat, and bone spurs began to protrude from his fingers, gradually turning into claws.
"Wake up!" The voice of Yin-Yang Evil Saint sounded behind his ears, and another clear light fell.
After his soul was cleansed by this clear light, Xiao Yan regained his clarity of mind and looked at the red-haired monster with fear.
Just a corpse could cause such strange things to happen to him. This kind of unknown fear often makes people more afraid.
However, when he looked at the top of the ancient monster's head, he found that there were two fish, one black and one white, swimming around.
"Yin, Yin-Yang Twin Flame?" Xiao Yan showed a trace of surprise on his face.
"Yes, this one is the real Yin-Yang Twin Flame." The Yin-Yang Evil Saint laughed.
"What about the one on the Yang side?"
"That's also a Yin-Yang Twin Flame!"
"You actually have two Yin-Yang Twin Flame?" Xiao Yan looked at the Yin-Yang Evil Saint in surprise.
"No, the Yin-Yang Twin Flame on the Yang side are indeed real, but it's just a seed fire."
After a pause, a strange smile appeared on his face and he said, "A special seed fire."
"Then the one you gave to Yao Ling is a fake?"
"You can understand it that way." Yin-Yang Evil Saint smiled and said, "Don't worry about it for now, I think you should take care of the crisis in front of you first."
"The crisis in front of me?" Xiao Yan was slightly stunned. When his eyes swept across the altar, he unexpectedly found that the weird monster actually stood up slowly.
In an instant, Xiao Yan's scalp began to numb.
"What kind of monster is this? If he rushes out, I will be dead!"
"This is..."
After a moment of silence, Yin-Yang Evil Saint showed a complicated and hesitant expression on his face.
"This is my corpse!"