Muramasa

It sits in the locked gold chests of the dungeon, which puts it behind Skeletron and behind a supply of golden keys. Golden lock boxes roll the same table, so fishing up dungeon crates is the patient alternative to walking the halls. There is a generation quirk worth exploiting: the first gold chest the dungeon lays down is usually the one holding this, so the very first locked chest you reach on the way in is where your first key should go.

Fast, and short. The reach is poor enough that you end up almost on top of whatever you are hitting, which is uncomfortable in the dungeon specifically. Each connecting swing sends a blue slash forward, but only the opening hit of a swing produces one, so wading into a pack does not turn into the wall of projectiles you might be hoping for.

The slash does not pierce and pushes nothing back, so it will not hold anything off you. What it does carry is armor penetration, which is unusual this early and quietly makes the sword better against heavily armored skeletons than the damage number suggests. Bring your own way to make space.

This is one of the four blades that feed into Night's Edge, and that sword is a far bigger jump than anything the Muramasa manages alone. Once one is in your inventory, treat the others as a checklist rather than settling in with this. Legendary is the modifier if you plan to swing it in the meantime.

Muramasa was a real swordsmith working in Japan in the sixteenth century. Later writing turned his blades into cursed things that drove their owners toward violence, which is the reputation the game is borrowing. The sword also picked up a Steam badge and, when swung, a trail of glowing particles.

At launch this was flatly the strongest weapon available. The swing rate combined with the knockback it had back then meant nothing standing in front of you could ever close the distance, and it took two separate rounds of nerfs before it stopped being the answer to every problem. It has drawn enough complaint since that the official 1.4.1 patch notes needled players about it in the header.