Sapphire Staff

Every gem staff behaves the same way. A single bolt, straight line, no pierce, and it stops dead on the first thing it touches. Against one enemy that is fine. Against a worm, a pack of slimes or anything that lines up in a row, each shot is spent on the front segment and everything behind it walks through untouched.

It fires while you hold the button now, which matters more than it sounds. Before that change the click per shot was the main reason people abandoned gem staves before they were actually outclassed.

Which one you end up with is mostly luck of the draw from your first few caves, and the steps between tiers are small enough that going back down to upgrade is rarely worth the trip. The Diamond Staff is the only one worth chasing deliberately, and the Space Gun makes the whole family redundant the moment you have meteorite bars.