A "monster" was sentenced to 22 years imprisonment for spiking two men with a drug, before raping and sexually assaulting the second.
Luiz Da Silva Neto (36), of Wandsworth in London, didpe the men at two separate events in a cottage in Oxfordshire last November and December.
According to Oxford Crown Court, both victims were found naked in their cottages and did not know what had happened.
One victim stated that he was happy to "protect others from this beast".
The police stated that they are keeping an open mind about the possibility that he might have committed additional offences.
Matthew Walsh, the prosecutor in the case, stated that Da Silva Neto had infused victims' drinks with GHB or GHL or a similar substance.
They are an "aphrodisiac", and can have "euphoric or hallucinogenic effects", according to him.
They are colorless and odourless. They are quickly absorbed by the body and are difficult to detect.
After he had taken him to work in Middle Barton, the first victim was able to drink alcohol at Da Silva Neto's property in Middle Barton. However, he "began feeling suddenly tired", according to the court.
After being sexually assaulted, he fell asleep completely clothed and woke up to discover that his body was "impossible to work" after waking up.
He felt "broken in two", but he left to see an empty syringe, and was convinced he had been drugged.
A jury found Da Silva Neto guilty of giving a substance that could be used to induce the consent of a man to sexual activity.
The second victim was at a London nightclub. He had only been married for a few months when Da Silva Neto drove the couple to Oxfordshire in a rental car.
After drugging him, Da Silva Neto made him undergo an attack in which he raped the man.
The victim was found naked in a "strange house" on the next morning, and returned home "confused, disturbed, and upset" to London.
He was reported missing and "couldn’t account for hours between leaving the bar to waking up in bed".
He told the court in a victim impact statement that he was happy he had helped to "break the chain" and protect others from the monster.
Da Silva Neto was found guilty of raping him and giving him a drug to make it impossible for him to have sexual activity in the cottage.
Judge Michael Gledhill, QC described Da Silva Neto a "sexual predator" by telling him about the second victim: "He wasn't more useful to you." He was a sexual predator. You had your way with him.
Judge said that the man was "completely traumatized".
The first victim stated in a statement that his life was forever changed and would never be the same. He said, "I live with this alone every single day."
He said that he had "severe anxiety" which made it really hard to "hear about the terrible things this man did me".
Da Silva Neto was ordered to serve at most two thirds of his sentence by the judge.
James Holden-White of Thames Valley Police described him as "very dangerous man", and the streets were safer with him behind bars. He used a well-practiced modus operandi.
He said that Da Silva Neto targeted heterosexual men because he thought they would be less likely to report the offenses to police.
"The bravery of the two victims is what made Da Silva Neto a convicted and imprisoned criminal."
Da Silva Neto was found not guilty of kidnapping the second victim, with the intent to commit a sexual offense outside of the nightclub, and administering a drug to induce him to engage in sexual activity in the car hire from London to Oxfordshire.
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