A tall, lean man dressed in tophat, greatcoat, and walking cane, at first glance he is a striking figure. Perfectly groomed. Personable. Perhaps even friendly. But the longer one looks at him, the more things seem...strange about Jack. His appearance looks as if one took a bit of this and a bit of that from every ethnicity known to humankind and arranged them in a handsome completed puzzle. His eyes are a strange, unsettling shade of violet. His dark blue brocade waistcoat is embroidered in swirling dark patterns of deep sea creatures--or at least what seems to be deep sea creatures. The head of his walking stick is an antique brass globe bearing strange engraved symbols. But the one thing that is truly terrifying about Jack is his smile. His unwavering, white-toothed, pleasant smile.
Jack's movements are always deliberate, yet graceful. He is methodical, like a dancer overly concerned with technique. Even taking a leisurely stroll is a bit too stiff and unnatural in its movement. He has no care for the personal space of others, and will use others' discomfort to his advantage if it suits his ends. True to his nickname, Jack is always smiling the same pleasant, friendly smile...even when he is enraged. He can often be seen twirling his walking cane, or inspecting the strange pocket watch he carries that not only measures time, but dimension and gravity, a photograph of two young children on the inner lid. Despite his unusual behavior, Jack abides the common rules of etiquette most often seen in the most elite of the aristocracy. A gentleman's gentleman.
Whoever, or whatever, Jack truly is, he is highly intelligent and extremely knowledgeable in the hard sciences. Chemistry, astrophysics, mathematics, engineering, neuroscience, and biology are all pet projects to him, and he possesses knowledge that lies hidden to many. When it comes to the soft sciences (psychology, arts, humanities, etc.) seem a bit lacking. He can easily replicate Da Vinci's The Last Supper to its original specifications, but he would not be able to convey what makes the fresco so moving, or its religious significance. But Jack can certainly be charming in his own way... if not outright manipulative.
It is not known if Jack was human at some point, or if his form is only a projection by an extradimensional creature. However, his archaelogical record reaches back centuries, if not millennia. In different clothes and appearances, but always as a mysterious trickster entity, sometimes helping and sometimes harming. More recently, he has been interfering once again in his home dimension, keen on removing some of his fellow Ancients from the playing field. To this end, ten years before his appearance in Ayenee, he has made a deal with a lady alchemist in the crown city of Haelgoria. The removal of several of her business rivals in exchange for allowing him entry into her world once more. The birth of the twin boy and girl who grace the photograph in his pocketwatch were not part of this deal. But they are an unintended (but not entirely unwelcome) consequence of their dealings.
