One odd touch of the story is that Poe starts out by telling the reader about the "grotesquerie" of Von Jung's family, even though it has absolutely nothing to do with the story:
The Baron Ritzner von Jung was a noble Hungarian family, every member of which (at least as far back into antiquity as any certain records extend) was more or less remarkable for talent of some description—the majority for that species of grotesquerie in conception of which Tieck, a scion of the house, has given a vivid, although by no means the most vivid exemplifications.
The real focus of the tale is that the odd baron has a special talent:
The beauty, if I may so call it, of his art mystifique, lay in that consummate ability (resulting from an almost intuitive knowledge of human nature, and a most wonderful self-possession,) by means of which he never failed to make it appear that the drolleries he was occupied in bringing to a point, arose partly in spite, and partly in consequence of the laudable efforts he was making for their prevention, and for the preservation of the good order and dignity of Alma Mater.
The way Poe sets up the story, it almost sounds like Von Jung's "mystific" talent may have something to do with mesmerism, which became a big thing in France of the 1770s. However, it turns out that Von Jung's "knowledge of human nature" is simply an extremely well developed ability to know how to press people's buttons. The unnamed narrator, after presenting a catalogue of Von Jung's pranks at his Alma Mater, finishes up by telling how Von Jung managed to get away with insulting a fellow named Hermann, known for killing numerous tormentors in duels. The devious Von Jung does so by knowing how deeply Hermann is versed in the *code duello,* and so works a psychological trick that makes Hermann desist from a dueling-challenge on a technicality.
The main significance of this lightweight tale is that Von Jung may be seen as an anticipation of the author's detective-character M. Dupin, who boasts a similar talent for sussing out people's secrets through an understanding of basic psychology. Poe also presents the reader with a very grotesque description of Hermann, noting that the man has "a trunk worthy of a Farnesian Hercules"-- and though his build has nothing to do with the story, its inclusion suggests that this is something of a "brain beats brawn" tale.
On a minor note, the "Tieck" Poe mentions in the first quote was a well-known German author, whose work is largely unread today, though as the link points out, his vampire tale "Wake Not the Dead" predated Dr. Polidori's "The Vampyre,"and appeared in at least one paperback collection of horror stories, as well as being available in translated form online.