Gu Tao made such a promise not because of Jing Yuan, his dog-like colleague, but because the Faraday cage he meticulously designed was valuable.
He made this decision because these three old men had a seniority and strength that were rare in the world. In the great web that Gu Tao had painstakingly designed, these three elders were among the most precise of knots, and they would surely become his most reliable guarantors and witnesses.
He believed that the three old men were well aware of this, but they had no way to refuse. Not every sage was peerless, and living in these times meant playing by the rules of the game. Crossing the tribulation was an incredibly difficult challenge, especially in an era when Spiritual Energy had not recovered. Who could withstand temperatures in the hundreds of thousands of degrees with their physical body alone? No one, Gu Tao could assure, not a single one.