Chapter 666: The Demon King's Inner Pill! The Secret of the Great Zhou Royal Family

"Demon King..."

Zhou Dao's eyes suddenly lit up like a bright lamp in the dark Big Tomb, firmly fixated on the terrifying figure before Emperor's Bridge.

A Demon King is a horrific existence comparable to a Human Tao Realm's strongest practitioners.

Such strength could gather a hundred thousand Demon Soldiers, claim a mountain as king, establish a Taoist Arena, and rival the Seventy-Two Demon Caves.

Since Zhou Dao had started his journey, he had never encountered a demon beast at the level of the Demon King Realm.

Even though it had long since fallen, the aura emanating from its corpse was still terrifying, as if its back was holding up a piece of the night sky, profound and vast, with a bright moon hanging high above, blooming in the depths of the Ancient Tomb, reflecting the figure of the Demon King.

"Great Dog Demon!?" Zhou Dao uttered with focus.