From the text:
Appearance:
Within, stood a tall old man, clean shaven save for a long white moustache, and clad in black from head to foot, without a single speck of colour about him anywhere.
"..... he moved impulsively forward, and holding out his hand grasped mine with a strength which made me wince, an effect which was not lessened by the fact that it seemed cold as ice, more like the hand of a dead than a living man."
It may have been that his breath was rank, but a horrible feeling of nausea came over me, which, do what I would, I could not conceal.
Behaviors:
"We are in Transylvania, and Transylvania is not England. Our ways are not your ways, and there shall be to you many strange things.
Blue Lights:
I asked him of some of the strange things of the preceding night, as for instance, why the coachman went to the places where he had seen the blue flames. He then explained to me that it was commonly believed that on a certain night of the year, last night, in fact, when all evil spirits are supposed to have unchecked sway, a blue flame is seen over any place where treasure has been concealed.