I've barely come back to this, but, the thought-process is more along the lines of spirits who take the form of a trusted/loved individual. So, for instance, when players control Hiroji, he encounters a spirit that takes the form of Gojo Sakura. It depends on how many doors he gets through before the encounter happens, but the spirit can easily claim that it knows the temple better than he, and knows of secret ways, and attempt to lure him that way.
As for the other two, they are less certain as to who they could encounter. The thought is that the Oracle encounters Kenshin for real, and Oharu encounters a faux-Momo, or maybe a faux-Queen-of-Askigaga (who is supposed to be dead).