Peter Madsen, 47, “expressed no remorse or guilt” over the death and dismembering of Kim Wall last August, a psychologist who examined him said.
During the tenth day of the trial, Copenhagen City Court also heard details of a blog post about heaven and hell which the inventor wrote.
Madsen is accused of murdering the 30-year-old journalist who never returned after going to interview him on his submarine.
Days later her dismembered body was found at sea.
Madsen admits dismembering Ms Wall’s body and throwing it overboard, but denies a charge of premeditated murder.
The court heard that during a psychiatric examination after he was arrested, Madsen “expressed no remorse or guilt in connection with the events”.
He was “strikingly lightly affected by the events” and was branded as “highly self-promoting and idolising” by the psychologist, the prosecution told the court.
The submarine owner told the psychologist that when he was a child one of his dreams was to be kidnapped and abused.
He also said he would go through with the trial out of “pure curiosity”.
During the hearing, the prosecution and defence entered into a feud over a blog post which Madsen had written.
His defence team read out his views on heaven while the prosecution concentrated on his depictions of hell, including threats which told readers to “go after the weak”.
On hell, Madsen wrote: “Hell is saturated by evil, penetrates your head as if you had wi-fi in the ear canal.
“The entire philosophy in this underworld comes to you.
“Go after the weak, they’re easy targets. If you want it, take it. Don’t settle for the scent, take a bite, sink and enjoy.”
An earlier female witness said he sent her a link to the blog post and said: “It is an entrance to my head.”
On heaven, he wrote: “You look around. A beautiful angel girl smiles her natural, pure smile at you.
“No makeup here. You think briefly, ahh she’s very pretty, actually pretty hot…”
In another post he wrote: “In submarines you could always trust.”
The court heard from Madsen’s lawyer that he pointed out to police where on the submarine’s route he had “dumped the different things” – presumed to be her body parts – but this was not officially recorded.
When police divers found the sunken submarine they discovered Ms Wall’s pants below a floor plate in an engine room and a broken, rusty utility knife blade.
The prosecution said this was important as they also found a utility knife in a plastic bag containing Ms Wall’s clothes, which was found weighted down at the bottom of the sea.
The court heard that Ms Wall’s DNA was found on Madsen’s face, by his nostrils, and on his hands, under his nails and on his neck when he was arrested.
No DNA was found around her genitals.
A blood splatter was found on his boilersuit, but a medical examiner said no splatter would occur after death, which is when he claims to have dismembered her.
The prosecution has said it will seek a life sentence, which in Denmark averages around 16 years, or safe custody, a legal alternative which would keep Madsen behind bars indefinitely as long as he is deemed dangerous.
The trial continues.