El Ravager said:A person's mentor is often described as 'their hero'. Dumbledore did plenty of heroic stuff, even if a lot is off camera or before Harry Potter was even born. Fighting Voldy, founding and being in the OotP.
Besides Obi-wan and Gandolf were both mentors and I would qualify them as heroes. Heck, Anikan was nominated as a hero and he eventually becomes the Villian who made it to the final round in the Villian showdown!