In comparison to a deepwater black serpent, a flood dragon’s blood would undoubtedly be purer and superior in quality. Hence, if dragon blood was to be offered to the Poisonous Dragon Water Control Flag, then its might would naturally grow much bigger.
Ye Xiwen began to refine the corpses of baby dragons one after another, and kept on adding their essences into the flag array. It could be said that there was a huge difference between his current and previous strength levels; even the degree of restoration of Tianyuan mirror was quite significant this time, which was also the reason why the refining of 'Poisonous Dragon Water Control Flag' took only one day.
This also included offering the 'blood of flood dragons' to the flag, which ultimately led to the evolution of all deepwater black snakes into flood dragons.