Dongying ninjas appeared even before the institutional system of the Dawn Harbor Emperor was fully established.
In history, the connection between ninjas and the Demon Clan was far less than those with Dongying's other two characteristic professions, Onmyoji and Witch.
The former absolutely required the skills to control demons, while the latter was naturally born with a synergistic and antagonistic relationship with the Demon Clan.
There were few tales about the interactions between ninjas and the Demon Clan.
The only thing worth mentioning is that there were indeed members of the Demon Clan in the history of ninjas.
The cultivation techniques practiced by ninjas were extremely unique. Unlike the Onmyoji and witchcraft which could only be practiced by humans, the ninja techniques were similar to those of cultivators and could be cultivated by both the ninjas themselves and the Demon Clan.