"That" helmet

A distinctive helmet (which was only referred to as "that" by John Constantine) was among the magical artifacts in possession of Jasper Winters.

History
At an unknown point in time Jasper Winters acquired the helmet through unknown means. John Constantine was aware of helmet's true power and when Liv Aberdine grabbed the helmet while she was first visiting her father's house, John warned her to put it down

Behind-the-scenes

 * In the DC comics such a helmet is usually known as Helmet of Fate. Granting it's owner with great magical powers it created quite a legacy of superheroes, most of which were known as Doctor Fate.