I think he was a past contractor of Sebastian's...
But didn't Sebastian say demons only get one contractor, so he can only have Ciel and no one else. Same goes to other demons
I said a past contractor not a current one and it's not the same for other demons. Other demons don't mind having more than one contractor at a time probably because the contractors don't last long. Modri Vladis could be a bizarre doll so Undertaker probably brought one 9f Sebastian's contractors back to life because he thought it would be funny.
*Of
In chapter 138.2, Sebastian said every demon has their own beliefs they stand by so not every demon is like Sebastian.
Ah my bad! I thought a demon can get one contractor one time in their life. Thank you for the clarification.
But what do you mean by "other demons don't mind having more than one contractor at a time probably because the contractors don't last long" you mean they can have multiple ones at the same time or when they finish with the current one they directly go to another? Because Sebastian said "only one contractor may exist at any given time. "
Sebastian said there are greedy demons out there that have more than one contractor and that's only Sebastian's rule. Like i said the demons were probably able to have more than one contractor because the contracts don't last long or they lie to them and just eat them without fulfilling their wishes then go find the other contractors to do the same thing. (Read the last couple of chapters of our Ciel's backstory to understand what im talking about.) Sebastian was ordered to not make more contractors while he is serving our Ciel so one contractor may exist at a time and he also isn't the type of demon to make more than one contractor (anymore) so that isn't a problem for him.
So who is this guy? Is he a demon like Sebastian or a human? Any speculations? I think he is another demon? That would be very interesting to see, two demons interacting with one another.