A man whose voice cannot be refused, which the series treats not as a superpower but as a description of an abuser.
Kevin Thompson, who renamed himself Kilgrave, is a man from Jessica Jones’s past who can control minds and whose reappearance takes her life apart. He was born with a neural disease and experimented on as a young child, which left him with an airborne virus that gives him his power.
David Tennant plays him as charming, funny and entirely without a floor, and the series is careful about why. Kilgrave is not written as a supervillain with a scheme. He is written as a man who has never in his life heard the word no and does not accept that it means anything, and every scene with him is about consent. It is the reason the first season of Jessica Jones is still the high point of this whole run.
Minor spoiler
Jessica kills him at the end of the first season. He returns afterwards only as a hallucination, which is the honest version of what happens to a person after somebody like him: the man is gone and the voice is not.