Chain Guillotines

Each use throws a pair of bladed heads out on chains one after the other, so a single click covers more ground than a normal flail head does. They keep traveling for a long way before they retract, and anything crowding you close gets cut by both blades on the way out. That makes it a good answer to a wall of enemies in a corridor, and a mediocre one against a single target that likes to keep its distance.

It comes off Corrupt Mimics, which wander the hardmode Corruption on their own but are much easier to summon deliberately with a Key of Night dropped into an empty chest. Farm them in a walled off room and you can force the drop instead of hoping one finds you.

Fire it forward while riding something fast and the chains cannot retract as quickly as you leave them behind, so a dozen of them end up hanging in the air at once. It looks silly and it also multiplies the damage you put into whatever you ride past.