The ability to share a collective consciousness between multiple bodies. Not to be confused with Mind Hive or Replication.
Hive mind allows a group of people (often biologically related) "share" the same mind. In some cases one person could take control of another separate body to add to the hive. Like most hive insects like bees and ants, each can work autonomously, though they think the same thing at the same time. The members have little individuality, more or less they are only marionettes controlled by a puppeteer.
In some cases the members of the hive mind have separate brains, mindsets, personalities, and individuality. But both are basically the same, all members work as one, they can all see, hear, and know what the others do. All work as one, each thinks with the same "mind", not as a sum of its parts.
Can be used to scout out areas being able to see and experience in multiple areas at once. If the subjects have any other powers they act as their own team or unit.