Which terraria accessories are worth chasing early hardmode?

wings before anything else, every fight gets easier once you can fly. after that your class emblem (warrior/ranger/sorcerer/summoner) from the wall of flesh. farm a mimic or two for the cross necklace and philosopher's stone. and if you never got a cobalt shield, get one now, it's the start of the ankh shield chain and knockback immunity matters a lot against the mechs.