Polarities Mod/Julia Shard

The Julia Shard is a craftable Hardmode magic weapon. On use, it fires a shard that quickly homes in on the player's cursor similarly to that of the Flamelash or Rainbow Rod, exploding into a wide-ranged spray of sparks once it reaches it, collides with terrain or an enemy, or the button is released. It is best suited for rapidly damaging dense clusters of enemies, coming in handy during events or against bosses that summon large amounts of minions.

Trivia

 * It is based on the Julia set fractal.