Mace

The name says mace but it behaves as a flail, and that changes what it is good at. Hold the attack button and the head orbits you, chewing on anything that walks into the arc; let go and it launches out and drags back. That orbit is the whole reason to carry one early. Zombies and slimes get hit repeatedly on the way in instead of reaching your hitbox, which covers the exact situation that kills new characters in a corridor.

It comes out of gold chests, so a couple of unhurried caving trips will usually turn one up long before you can craft anything comparable. On modifiers, take Ruthless over the crit options here. The numbers involved are small enough that rounding eats most of the value a crit chance would give you.