Lead Shortsword

Instead of an arc, it stabs straight out and pulls back. Since the 1.4 change the stab follows your cursor, so you can poke down into a hole you are digging or up at a bat without turning around first. The animation is quick, but the reach barely clears your own hitbox.

That reach is the whole problem. Landing hits means standing close enough to eat contact damage, which is fine on slimes in the first minute and bad against anything that moves with intent. The broadsword made from the same bars covers a wide arc and can catch several enemies at once, so craft it as soon as you can spare the metal. The Iron version plays identically, so use whichever ore your world rolled.