In the episode 'His Last Vow', what is the name of the newspaper magnate villain?

The newspaper magnate villain in “His Last Vow” is Charles Augustus Magnussen. Played by Lars Mikkelsen, he is a powerful media proprietor who uses private information as a weapon.

Magnussen is Sherlock’s principal adversary in the third-series finale. He possesses “pressure points”—damaging secrets about influential people—and maintains a vast mental archive of them. His power comes less from physical force than from knowing exactly what will make another person obey him.

His interest in Mary Watson’s past brings him into direct conflict with Sherlock. Magnussen threatens to expose Mary’s identity and exploits the information to control John and others. The episode’s title refers to Sherlock’s attempt to protect Mary and stop Magnussen from releasing his secrets.

A common mix-up is confusing Magnussen with Jim Moriarty, Sherlock’s earlier criminal mastermind. Moriarty is the major antagonist of the first two series, while Magnussen is the newspaper owner introduced in series three. Sherlock ultimately kills Magnussen at Appledore because he realizes the evidence cannot be safely removed by any other means.