Fortunately, everything went smoothly. The Green Flood Dragon wouldn't have thought it had already become Tang Feng's beast pet.
Tang Feng was just acting on a whim and had no plans to take it out. The Supreme God Relics would open again after a million years, and when the disciples of Tang Sect came in, having this flood dragon there would basically ensure their safety.
This Green Flood Dragon had been imprinted deep in its soul with the mark to protect Tang Feng's disciples. As soon as it heard about the disciples of Tang Sect, not only would it not harm them, but it would also protect them. As for why, it probably wouldn't understand at that time either.
To keep the Green Flood Dragon safe, Tang Feng had set up several hundred defensive formations on it, making it strong enough to get through the crisis.
With the speed of Tang Feng's Divine Ship, escaping safely was not a problem.