Quentin Beck was a supervillain in the Earth-2345678 universe. He was killed by Spider-Man.
Quentin beck was a special effects artist many years ago. One day he decided to use his skills to become the Supervillain Mysterio. During his career he fought many heroes mostly the Amazing Spider-Man. After years of defeat he became obsessed with the wall-crawlers demise. To the point of him losing his own sanity. In his final attempt to ruin Spider-Man he donned his costume then killed a little girl. The public thinking Spider-Man was at fault hunted him. Mysterio was eventually revealed by Spider-Man to be the actual killer by Spider-Man. He was brutally beaten then had his heart ripped out by the hero.
Genius level intellect: Has the mind of a genius
Weapons expert: Is a master to many types of lethal weaponry
Escape Artist: He is a skilled escape artist to aid in his gambits