Light's Bane

Each swing throws a short dark slash off the tip that snaps toward anything standing nearby, which quietly extends your reach past where the blade actually is. Those slashes cut through armor, so the sword holds up against the tankier pre-Hardmode enemies better than the raw number suggests.

Your melee crit chance doubles as the odds of a much larger slash coming out instead, so crit is worth more here than on most early melee weapons. Against the Crimson equivalent it trades size and weight for speed, which suits it to swarms in narrow corruption tunnels rather than to single heavy targets.

It is a component of the Night's Edge, and that recipe is one of the better reasons to visit both evil biomes and the dungeon before the walls go up. Keep it in storage even after something stronger turns up.