The Lead Wizard was a Hardmodegun that dropped from Golem in Malice Mode. When fired, bullets were transformed into yellow high-velocity bullets that shoot out from the gun at angles above and below the cursor's position forming roughly a 30 degree angle.
This weapon's name was a reference to The Wiz from The Binding of Isaac: Rebirth, which also makes the player's shots fire at a 30-degree angle away from wherever they are aiming.
This weapon's tooltip was a reference to an earlier version of the mod in which this weapon did not work correctly, instead shooting bullets erratically from the player and not from 30 degrees away as mentioned above.
This weapon performed well against worm-type enemies, due to their size allowing both streams of bullets to hit.