Viscera

The Viscera is a craftable post-Moon Lord wand. It acts similarly to the Shadowbeam Staff, in that it fires a beam that bounces off of walls and pierces through enemies. However, the Viscera also heals the player for every enemy hit per beam.

The beam's base healing value is 1, which gets multiplied by 1.4 for each time it bounces off of tiles or hits an enemy. The beam can only bounce or pierce 6 times, therefore capping the max healing per beam at about 8.