Gladius

Shortswords are normally the thing you drop on the floor, and this is the exception, because one press runs a quick sequence of stabs rather than a single poke. The thrusts come out at slightly different angles, so the burst sweeps a small area instead of hitting one exact pixel. Against something that holds still it is a real weapon for its tier, not a novelty.

You stab straight ahead at arm's length, which means standing inside the hitbox of whatever you are killing. Marble caves are where it drops and also where it is most awkward, since the hoplites that carry it lob spears from across the room and you have to cross that room to use it. Bring something ranged for the approach and finish the job up close.

The Starlight uses the same multi-hit attack with numbers from a much later part of the game. Think of this as an early sample of that style rather than something to hold onto once hardmode opens up.