Holy Arrow

An arrow that dies calls a star down onto the spot where it died, and wherever that star lands a second one follows. Both drop in from the top of the screen and pass through solid ground on the way, so cover between you and the target does nothing to stop them. Each star hits once and stops there, but arrow plus pair is a large multiplier over the arrow on its own when everything lines up.

Nothing falls unless the arrow is destroyed cleanly, meaning it hit an enemy or a block. An arrow that sails off the edge of the screen and despawns produces nothing at all. The second star depends on the first one ending the same way, so a first star that fails takes the rest of the sequence with it. Long potshots into open air waste most of what you fired, and the stars ignore the velocity boost from a Magic Quiver.

Big, close and slow. Plantera is the classic pairing, especially out of a Chlorophyte Shotbow, and multishot bows like the Tsunami multiply everything because every arrow that connects starts its own pair. They hold value well past Golem and are one of the better answers to the Martian Saucer even in Expert. Against small, fast enemies most of the star damage never lands and a plain hard hitting arrow does more.

• The area they cover dwarfs Hellfire Arrows, but hellfire goes off exactly where you aimed every time, and you can buy it before Hardmode instead of farming a biome.
• Jester's Arrows pierce in a line you choose. Holy Arrows pierce vertically whether that helped or not.
• Cursed and Ichor Arrows hit harder per arrow and bring a debuff along, and their materials come off surface enemies rather than out of the Hallow.
• Chlorophyte Arrows and Luminite Arrows both correct their own aim, which makes them steadier on erratic targets.

The arrows glow in flight and the stars light everything they pass through, unmined ground included. In a dark cavern that is a real navigation aid, and because the stars travel through terrain they can reach enemies tucked into pockets a straight shot cannot touch.