56 comes from the Ancient Plane search
Ye Jiu had quite a hard time explaining to the person opposite him what a plane trading device was, and at the same time, he also learned that the other side was not just an Ancient Plane but also a Beastman's world.
His name was Cha, a lone wandering Beastman who had been injured while hunting prey and accidentally dripped blood onto a pretty stone he had picked up. Then a trading screen appeared in front of him, and by a twist of fate, he hit the video request button, which is how he came to see Ye Jiu and got quite the scare, mistaking Ye Jiu for a deity.
Since Cha was quite naive, he was easily coaxed into conversation by Ye Jiu. Cha's plane trader was different from Ye Jiu's; Ye Jiu's resided within his mind—if one had to say there was a vessel, then it would be Ye Jiu himself.
Cha's, however, existed within a stone; he had to wear the stone on his person in order to control the plane trader.