The Harvester siphons the souls of the dead, before releasing them into a cluster hex of power.

This mystical item siphons the energy of lost souls and redirects that power as an attack of into energy against any mobs surrounding you. It's an excellent item to use when you find yourself at low health and with little chance to escape.

The Harvester has a 4 second cooldown, +1 soul gathering, and requires 40 souls to activate. Equipment that increases Artifact Damage, such as the Souldancer Robe, Splendid Robe, and the Cave Crawler affect the amount of damage dealt.

The Harvester creates a circle that damages mobs within it with a high-energy blast, dropping any loot.

The link: https://minecraft.fandom.com/wiki/Minecraft_Dungeons:Harvester

The damage range depends on the item's power.