He met Ji Ishwin when Ishwin was travelling in an adventure. He chose to follow Ishwin because he saw that Ishwin had potential and chose to be his spirit beast.
He is the first spirit beast that Ji Ning meets. Ning meets him right after being born. Ning is surprised by how big of a snake Black is and also the fact that Black transformed into a black haired middle age man. He is next seen when Ning is four years old and wants to train in Fiendgod Body refining technique. Black brings the 19 tomes of Fiendgod body refining techniques from the Ji Clan's library and gives it to Ning to read. Each of the tomes has the description of a Fiendgod body refining technique and they are abridged versions. He then leaves after that.