Chen Hao's divine sense roamed through the formation's patterns like fingers tracing Braille. "So it needs a demonic beast's essence blood," he murmured.
Not just any demonic beast would do. It had to be an exotic beast from the Primordial Era with a sufficiently pure bloodline. Ordinary demonic beast blood could not open it.
Chen Hao withdrew his hand, closed his eyes, and extended his divine sense into the Qiankun Bag. More than ten thousand kinds of items were piled inside.
He searched through heaps of magical artifacts, pills, cultivation manuals, and ores before finding a small jade vial in a corner.
The vial was no thicker than a thumb and snow-white all over. A yellowed label on it bore three ancient characters—Phoenix Essence Blood.
Back in the Primordial Era, he had saved an injured Phoenix. To repay him, the Phoenix had given him three drops of its lifeblood essence. He had put them in the Qiankun Bag and never thought of them again.
He opened his eyes and took the jade vial out of the Qiankun Bag. The instant he pulled out the stopper, a scorching aura surged from its mouth, warping the surrounding air.
A crimson-gold drop of blood floated out of the vial and hung in midair like a miniature sun, radiating dazzling light.
"Is that..." Cai Jingwen instinctively took a step back. The searing heat made her skin feel tight.
With a wave of Chen Hao's hand, the drop of Phoenix Essence Blood shot into the groove on the boulder's surface.
The stone shuddered, then began to glow. Patterns spread outward from the groove in every direction like a net catching fire.
The sand and stones underfoot began to sink, revealing an opening leading downward. A staircase descended step by step, its bottom nowhere in sight.