Aqua Scepter

It throws two arcing jets per press and they fall as they travel, so aiming means leading upward rather than pointing straight at things. Angled correctly a stream crosses most of a screen and a half before it lands. Each jet passes through several enemies before it stops, which is what the weapon is really for: a packed corridor takes the whole spray at once, while a single target takes one thin hit at a time.

A stream still falling when it meets lava kicks back upward, and it changes completely on the way up. It slows down, stops caring much about gravity, lasts far longer and pierces without limit. Put a shallow lava pool between you and whatever you are fighting and the crowd clearer becomes a sustained single target weapon. Each stream gets one bounce and only while descending, so the pool has to sit below your firing line for any of it to work.

The streams apply global invincibility frames, which means the two jets from one press usually cannot both land on the same enemy. Mythical is still the overall pick, but a Sluggish roll spaces the shots far enough apart to sidestep the overlap, and against one or two small enemies it genuinely out damages the fast version. Put it in front of a crowd, where every jet finds a different body, and the fast roll wins again.

It is one of the possible contents of the locked gold chests in the Dungeon, so it costs a Golden Key and some luck rather than a fight. Golden Lock Boxes draw from the same list, so if you are opening those you have a second source. Expect to go through several before it turns up.

The pierce and the reach make it a real option for a magic character at the Wall of Flesh, since you can hang back and let the jets rain down on the Hungries and the eyes together. After that it fades out. The Golden Shower covers the same job in Hardmode with an armor shredding debuff attached, though it is a book rather than a wand.

In Remix and Zenith worlds this weapon and the Bubble Gun trade places entirely. The scepter stops appearing in Dungeon chests and drops from Duke Fishron instead, arriving with late Hardmode damage and fire rate and using local invincibility frames rather than global ones. In those worlds there is no argument about the reforge: take Mythical.