Telepathy

Melzargard! Return to the ship! The intruder takes priority.Telepathy (テレパシー, Terepashī) is the ability to know what is in someone else's mind, or to communicate with someone mentally, without using words or other physical signals.

Overview
The user is able to read another person's thoughts, communicating with them mentally. This ability usually belongs to espers.

Telepathy is first used in the series when Slugerous attempts to communicate with Kamakyuri, and realises that the latter was killed by Saitama.

During Melzargard's battle against the other S-Class heroes, Geryuganshoop is shown using telepathy to mentally communicate with him, telling him to return to the Giant Spaceship.

After Garou awakens from the unconscious state due to his battle with the heroes, Gyoro Gyoro uses telepathy to communicate with the Hero Hunter, telling him to stay hidden while he deals with the other members of the Monster Association.

During his battle against Child Emperor, Phoenix Man has showcased some sort of telepathic ability, allowing him to mentally communicate with the hero. More remarkably, Phoenix Man is even able to connect his and Child Emperor's spirits to a spiritual space, a place that is separated from the real world where he and the child hero can communicate with each other as well as see each other's appearance, even though their physical body isn't there.

While being restrained by Tatsumaki's unrivaled psychic powers, Psykos attempts to communicate with Overgrown Rover using telepathy, asking for the executive's assistance.

18 years ago, Blast had a conversation with Tatsumaki after saving her from a hybrid monster. Upon placing his hand on her head, he saw a vision of Fubuki and could tell that she's her sister. Due to this, it is implied that he may have some sort of psychic or mind-reading ability.

Later, when Tatsumaki falls unconscious due to exhaustion from the battle against Psykos and Orochi. Fubuki uses telepathy to psychically contact her.