Sorcerer Emblem

The Wall of Flesh hands out one emblem from the class set per kill and picks it at random, so getting the mage one specifically is a matter of repeat runs rather than skill. That is fine. The fight is short once you have a hellbridge and any early hardmode weapon, and you want the other emblems anyway.

The reason to keep killing it after your class emblem drops is the combined emblem, which folds all of them together and then feeds the later accessory line. Wear this one through early hardmode, then plan on consuming it. Percentage damage bonuses like this scale with every weapon and buff you stack on top afterward, so it holds value far longer than the flat bonuses you find around the same point.