Minecraft Dungeons:Conduit

"Creates a sphere of oxygenated water, protecting players from drowning and damaging certain mobs"

- In-game description

The Conduit is an artifact in Minecraft Dungeons that will likely become available in the Ocean DLC. The only proof of it existing is a name in the game files along with a description. It will protect players from drowning and will also damage some aquatic mobs.