Short answers, pulled from the story.
Magic Alex was the nickname given to Yannis Alexis Mardas, a Greek-born man who became closely associated with the Beatles between 1965 and 1969. John Lennon gave him the nickname after being fascinated by a small plastic box with randomly blinking lights that Mardas called the Nothing Box. Mardas became head of Apple Electronics, the Beatles' in-house technology operation.
In January 1969, the Beatles arrived to use the studio Mardas had been tasked with building in the basement of Apple headquarters on Savile Row, only to find an unusable space. There was no 72-track tape machine as promised, no soundproofing, no intercom system, and no patch bay. The only new piece of equipment was a crude mixing console described as looking like "bits of wood and an old oscilloscope." George Harrison called it "the biggest disaster of all time." It was estimated that Mardas' schemes cost the Beatles at least £300,000.
While in India in 1968, Mardas reported to John Lennon and George Harrison that Maharishi Mahesh Yogi had made a sexual advance toward a young American student and toward Mia Farrow. He warned that the Beatles had to leave immediately or face "black magic." He went to Dehra Dun to arrange taxis for their departure. Cynthia Lennon believed Mardas invented the story to break the Maharishi's influence over Lennon, and both Harrison and McCartney later apologised to the Maharishi.
It was estimated that Mardas' ideas and projects cost the Beatles at least £300,000, with most of that sum considered to have been spent around 1968. Apple Electronics was closed by the Beatles' manager Allen Klein in 1969 when he took over management of the band.
In the 1970s, Mardas set up companies selling armoured vehicles and security hardware to VIPs, using former King Constantine II of Greece as his salesman. The venture produced repeated failures: the Sultan of Oman's armoured Mercedes exploded during a live-fire test in July 1977, destroying the car. King Hussein of Jordan had a fleet of customised cars tested in November 1977, where bullets easily pierced the armour-plating, and Hussein ordered the vehicles returned to their original state.
In 2008, Mardas sued The New York Times in England after a reporter called him a charlatan in an article about the Maharishi. He won the right to continue his defamation case on appeal in 2009. Mardas ultimately dropped the case on condition that the paper clarify its meaning. On the 4th of March 2010, the Times published an editor's update stating the article had not accused Mardas of fraud or criminality.