Relics are pieces of equipment that increase stats for your heroes. Some relics can only be used in PvP, some only for defense, and some only for attacking. You can use a forge (scroll down on the relic page) to upgrade relics but it requires a lot of materials.
Ok so I have a 6⭐️ Cursed witchbroom from the “Fennec Fright Fest event” but I was wondering what it means at the bottom of the details when it says “Relic Target” and then “Targets all special hero’s” what do they consider to be a special hero? Like the event hero?