 The character shares many similarities with Marsters 's Buffy the Vampire Slayer and Angel character , Spike , with Marsters commenting " In a lot of ways , this role is very much like Spike was in my first three episodes of Buffy . " The Torchwood writers conceived John as a classical nemesis for Captain Jack , with Chibnall commenting , " In seeing John you see the way Jack could have gone , and probably did , for a little while . " James Marsters further discussed ways in which John is a doppelgänger or foil to Captain Jack : both are pansexual time travellers , with their key difference being that John never reformed . The character exaggerates many of Jack 's qualities , for example displaying <unk> attraction to non @-@ humanoids such as <unk> , in addition to men and women . John and Jack 's intentional similarities extend to their penchant for period war clothing : 
