Vajramuni was born as Sadananda Sagar on 11 May 1944 in Bangalore. Considered one of Kannada cinema’s finest actors, he was known for his thundering voice and sterling performances, which earned him the sobriquets Nata Bhairava and Nata Bhayankaa. Equally skilled at playing villains and comedic roles, he was recognized for his ability to bring a breezy naturalness to the characters he enacted onscreen.
Like many other actors, Vajramuni was also a product of his participation in Kannada amateur theatre, which provided him with a sound base to pursue a career in films. Though his father was a corporator, Vajramuni was pulled not towards politics but theatre. Having dropped out of college—though he had secured a diploma in cinematography—he travelled to Mumbai for an audition. He was selected immediately with his impressive background as a member of Ninasam, the hub of Kannada theatre and cultural activities. His talent was noted by the famous lyricist and dialogue writer Kanagal Prabhakar Shastry, the elder brother of Puttana Kanagal, who cast him in the title role in the play Prachanda Ravana. Carried by his considerable histrionic skill, the play became a raging hit.
Bowled over by Vajramuni’s brilliant performance in Prachanda Ravana, the director Puttanna Kanagal picked the young man for his ambitious Saavira Mettilu project. However, this project did not take off, but Puttana Kanagal promised Vajramuni that he would feature in his film. He kept his word with Mallammana Pavada (1969). Only 23 years old, Vajramuni played the menacing villain of the film against the thespian Dr. Rajkumar. His ease on screen and the panache with which he pulled off the character saw him featured in film after film as the villain. He soon became to Kannada cinema what Amrish Puri was to Bollywood. As a ruthless landlord, a vainglorious son, or an angry sage, Vajramuni was a regular feature in a majority of films starring Dr. Rajkumar. With his guttural dialogue delivery and piercing, fiery eyes, he brought his own unique stamp to each of the characters he played.
Vajramuni acted in over 300 films over the course of his career. He played the villain in various movies of the 1970s like Bangarada Manushya (1972), Mayura (1975), Shankar Guru (1978), Upasane (1974), Bahaddur Gandu (1976), Babruvahana (1977), CBI Vijay and Sipayi Ramu (1971). The hero-villain combo of Dr. Rajkumar and Vajramuni became synonymous with good and bad in the universe of Kannada cinema, and the two would set the box office aflame together. Though Vajramuni played mostly villains, he also delivered critically acclaimed performances in films like Gowri Kalyana (1991) and Raayaru Bandaru Maavana Manege (1993). He also produced some films, including Ganda Bherunda (1984), Thayigintha Devarilla (1977), and Brahmastra (1986)Brahmastra. However, these films did not do well at the box office.