The jury was told of the last hours of Christopher Rogers, the Labour councillor who was a satanist and a homosexual addicted to sado-masochism.
He was stabbed to death by Colin Henry, a 37-year-old joiner, after a row over satanism at Mr Henry's home in Carlton, Nottingham. Mr Henry has denied murder.
Mr Rogers, 40, was staying with Mr Henry and another man, Paul Simmonds, for the weekend in February last year. Mr Henry, who has described himself as a 'bonded priest' in the witchcraft cult, said he could remember little about the killing.
Dr David Gill, his psychiatrist, told Nottingham Crown Court: 'Henry had been subjected by Rogers to what I would describe as torment. He tormented Henry about what part of his body he would like to have cut off. He talked about his involvement in the abduction, torture and death of four or five young men.
'He attempted to convert Henry to his own perverse beliefs in satanism. Henry seemed to have been overwhelmed, distressed and humiliated by this.' Dr Gill said Henry was 'really repulsed' by Rogers, adding: 'He believed Rogers had mental powers to manipulate him.'
In an interview after his arrest, Henry told Dr Gill that he picked up a sheath knife and said to Rogers: 'So I am stupid am I?' Rogers came towards him and Henry lashed out. Dr Gill said Henry told him: 'Rogers jumped over a foot stool and came for me again. I struck him again with the knife and he fell . . . to the floor.' Henry shouted at him: 'You are not going to call me stupid any more.'
The case is expected to end today.