The Wicked Hood functions the same way as a talisman, granting access to the Runecrafting altars. Before it can serve this function for any given altar, you must "feed" the talisman or tiara corresponding to that altar to the hood. One hood can serve as a tiara for all altars, once one of each talisman (or tiara) has been fed to the hood. If you lose your wicked hood, you can get a new one for free from Tam McGrubor, and all of the altars you had unlocked previously will still be unlocked.