A teacher who was duped into handing over £300,000 by a bogus spy says he fell victim to the conman's "unusual powers of persuasion".
Mr Atkinson said the conman was "just sick"
Convinced by tales of undercover work and IRA terrorists, John Atkinson said he was beaten during a string of "tests" to prove he was a worthy.
Robert Hendy-Freegard, 34, of Blyth, Notts, was jailed on Tuesday for life for theft and kidnapping-by-fraud.
Mr Atkinson said outside court that he felt vindicated by the sentence.
Hendy-Freegard cheated his eight victims out of almost £1m during almost 10 years of deception.
Mr Atkinson, now an English teacher in Prague, told how he carried out a string of "bizarre missions" for Hendy-Freegard, convinced that "my country needed me".
Mr Atkinson said: "This is somebody who ruins lives, he ruined my life and ruined many other people's lives.
"He did put me through hell. It was degrading and humiliating."
Mr Atkinson said: "They were very serious things that he was lying about, you do not joke about the IRA. He is just sick.
"I have heard him described as an narcissistic sociopath and that seems to sit pretty well. It is all about himself. He will tell any lie just to get what he wants."
John Atkinson, 34, Cumbria
Maria Hendy, 37, Frome, Somerset
Sarah Smith, 34, Thanet, Kent;
Simon Young, 35, Conisborough, Doncaster
Elizabeth Richardson, 34, Deepcar, Sheffield
Kimberly Adams, 33, Reading, Berkshire
Caroline Cowper, 38, Chiswick, west London
Renata Kister, 32, Fulham, west London
Mr Atkinson said he had "hit the ground with a bump" when he found out the truth about Hendy-Freegard but said it was now all in the past.
He described the conman as "pretty intimidating and pretty mean" but said he had not feared for his life.
"I have dealt with what has happened and I have recovered pretty well, I think," he added.
Caroline Cowper, another of Hendy-Freegard's victims, said outside court: "It was a shame the sentence could not have been longer. He is a danger to society."
Sarah Smith, who gave him more than £200,000, recalled once being ferried to a so-called "safe house" with a bucket over her head.
Most of the victims gave evidence from behind screens, explaining how the relentless manipulation of their lives had left them with huge debts and shattered emotions.
Hendy-Freegard, who worked at a pub in Newport, Shropshire, when the con began in 1992, told the victims he was an MI5 agent and that they were being hunted by the IRA.
He was jailed for life and must serve a minimum of 10 years in prison.