Tan Yun guessed right, Yun Xiao truly had no strength left even to lift his arm, and he knew why that was the case—it was because the activation of the Ancestor Vein Power just now wasn't quite the same as the one over a year ago at the Shang Family's place.
Back then, Yun Xiao had activated the Ancestor Vein Power several times, even using the Meridian Fire to leave the mysterious, tall and thin old man disheveled, but such a situation had never occurred at that time.
Yun Xiao, who had collapsed to the ground, pondered briefly and seemed to have understood a bit; those few life-threatening moments were autonomously triggered by the Ancestor Vein Power, consuming perhaps not his own strength, but something deep within his body.