The power to use oneself as a telepathic relay station to communicate with multiple people. Technique of Telepathy.
The user can use their talent with telepathy to act as a "relay station" for a group of minds, allowing said minds to "speak" to one another through the user.
Martian Manhunter (DC) uses his telepathy to allow the Justice League to communicate with each other.
King/North Kai (Dragon Ball Z) acting as a relay station to allow Son Goku and others to communicate.
Inoichi Yamanaka (Naruto) uses the Mind Body Transmission Technique to act as a telepathic relay station for the Great Shinobi Alliance...
...and uses the Mind Body Transmission Technique to allow multiple people to telepathically communicate with each other.