Wikipedia: Tokyo Subway Sarin Attack

Aum Shinrikyo was founded in 1984 as a yoga and meditation class, initially known as Oumu Shinsen no Kai (オウム神仙の会 "Aum Mountain Hermits’ Society"), by pharmacist Chizuo Matsumoto.

Later, Matsumoto changed his name to Shoko Asahara and masterminded the most deadly terrorist attack in Japanese history. Asahara was executed by hanging on July 6, 2018, at the Tokyo Detention House, 23 years after the sarin gas attack, along with six other cult members.

The Untold Story of the Bastille Day Attacker

"Some in Nice knew the man as one of the many playboy predators the city seems to beget—black hair slicked back off a shining brow, dress shoes tapering to varnished points, a dark shirt unbuttoned low to reveal the pectorals into which he had obsessively, unblushingly, invested himself. He was 31 but preferred older women, both for their erotic openness and, it seems clear, for their money. Those who knew him best knew him to be a cold and brutal man, detached, amused by little save rough sex and gore."