Note that Season 3 combines the Hongyue (Arc 3) and Northern Kingdom (Arc 4) chapters. So Season 4 would refer to Story Arc 5 (Yan Ruyu), Season 5 would refer to Story Arc 6 (Southern Kingdom), etc.
At least that's how their official weibo channel orders the seasons (can use translate tools):
https://weibo.com/huyaoxhn?refer_flag=1005055013_&ssl_rnd=1607248811.5053&is_all=1
So they say Mutiancheng arc is Season 9.
What do you think?
