Foster Christian started a life sentence in October for the two murders and two woundings following his trial at Maidstone Crown Court.
Giving him a 30-year minimum tariff, Judge Mr Justice Stuart-smith branded Christian a liar who had fabricated a story about Simon Gorecki attacking him.
The judge said: “I don’t know if you have ever stopped pitying yourself, or deludedly thinking that you can justify what you did, long enough to consider the impact your knife attack had, not just on the people you attacked and wounded, but on those affected by the loss of life you caused.”
Christian’s sentence was greeted with cheering in the packed courtroom.
The killer reacted by extending his middle finger towards friends and family of the victims.
Two women from Canterbury were also sentenced for their part in Christian’s crimes.
Naomi Toro, 37, of Keyworth Mews on the Brymore Estate, was jailed for a year after she disposed of the knife Christian had used by throwing it into the Stour at Fordwich.
Samantha Groombridge, 20, of Downs Road, was sentenced to 10 weeks youth custody after helping to conceal the knife.
Natasha Sadler-ellis’s family have particularly campaigned to ask the Crown Prosecution Service to call for a review of the women’s sentences on the basis they were too lenient.