Withersbane

The Withersbane is a Gold sword with the ability to spread its damage from undead entities to other undead entities. Entities considered undead include Skeletons, Wither Skeletons and Zombie Piglins.

Obtaining
The Withersbane can be found in a small room at the center of a round table representing a war map in the Forbidden castle.

Possible upgrades
The Withersbane can be upgraded with any sword enchantments. Having it in your hand while having an armor enchanted with Thorns can activate its damage spreading between undead entities abilities.

Description
An ancient blade to smite the impurity from the Nether

Theories
TBA