Blood Thorn

Thorns burst out of solid ground around wherever you are pointing. Aim at open sky with nothing underneath and they sprout from you instead, which is a much worse version of the same weapon. Platforms count, so a layered arena keeps it working at altitude, but a bare bridge over a void will not.

Carry an Ice Rod and you can grow the ground yourself. Drop a block of ice anywhere in midair, point at it, and the thorns come out of that. It turns the weapon's biggest limitation into a two-step routine and lets you fight anywhere. It costs a slot and a moment, and it is worth both.

If a wall sits between you and your cursor, the thorns appear at the wall rather than past it, so you cannot reach around a corner the way you can with a projectile that ignores terrain. Keep line of sight to what you want dead. Each thorn can strike the same enemy more than once before it fades, so put them where something is going to stay rather than where it is passing through.

The sharks that drop it only turn up when you fish during a blood moon, so getting one means committing an entire blood moon to standing at a lake with a rod out. Odd way to spend a night, but the weapon holds up through most of early hardmode.