Bring a Wand to a Knife-Gun Fight

When Harry took a Killing Curse to the chest, he figured that he would, you know, die. And he was fairly certain the afterlife wasn't supposed to have a devastating demon infestation. Guided by his so-called 'saving people thing,' he takes up the mantle of Huntsman and prepares to face off against the Grimm as the only wizard of Remnant... He IS the only wizard of Remnant, right?