In fact, regarding the war advice from the Painter, Ning Zheng has no right to refuse.
Because now the Painter's family is extraordinarily powerful; if a fight really breaks out... Ning Zheng wouldn't be able to match him.
Firstly.
All the Half-Celestial Phenomenon powerhouses from Xi Rong have ascended to prehistoric times.
It seems his forces have been explosively growing, but in reality, the growth is all in the "past" realms.
Secondly.
It's always Xi Rong holding the front line.
The Painter, that Old Deng, hides in the background as the mastermind, collecting too much data.
There was not only the previous Immortal Venerable Changzhen, End of the Dharma Immortal Venerable, but also Ning Zheng's own Shadow Crocodile Immortal Venerate and Golden God...
These four great powerhouses, Ning Zheng truly can't beat his painters.
In summary.
Ning Zheng now has to act according to the Painter's wishes.
