Given Fang Bai's cultivation level, he fundamentally cannot participate in the battle between the Demon Clan expert and the Roaring Arhat, who is an Immortal Emperor Realm expert.
Therefore, his approach to assisting the Roaring Arhat wasn't to fight personally, but rather to use the Thread Condensation Sound Transmission Technique to guide the Roaring Arhat on exploiting the weaknesses in the Demon Clan expert's attack and defense to defeat him.
Once the Invincible War Emperor, Fang Bai today, despite lacking cultivation level, still has a keen eye. He swiftly discerned numerous flaws in the Demon Clan expert's attack and defense and promptly informed the Roaring Arhat.
The Roaring Arhat was initially surprised to hear Fang Bai's voice. However, he soon realized that the flaws Fang Bai pointed out in the Demon Clan expert's attack and defense indeed existed, which delighted him beyond expectation.
