Javelin

It runs dead flat for a long stretch and then drops off a cliff rather than arcing down gently. Anything past that flat stretch has to be aimed above. It punches through a small number of enemies and then stops, and it never lands as a pickup, so every throw is spent for good.

Crowds. Slime rain, blood moons, anything that funnels bodies into a line clears faster with these than with a single-target weapon, because the piercing and the throw rate work together. Against one large enemy it is unremarkable.

Hoplites drop them in bulk, and a Hoplite Statue turns that into an assembly line. That is the only sane way to keep a few thousand in a chest, and it is worth doing before an event rather than during one.