Court heard that Boy B didn't want to be Boy A's friend and was afraid of him - but he gave him some kudos
Boy A was one of his closest friends, Boy B told gardaí - but was "weird, not a rational thinker".
Asked by gardaí if Boy A was a goth, Boy B said "no, he's more strange".
Boy B's father also gave evidence that his son told him he was afraid of Boy A as he had "lots of power".
Dr Colm Humphries, who was called as a witness by Boy B's legal team, alleged Boy B was "quite lonely" and needed to be with his peers to create a place for himself.
A clinical psychologist, Dr Humphries, claimed Boy B didn't want to be Boy A's friend, and he was somewhat afraid of him. However, he said Boy A could give Boy B some kudos because he was a little bit different.
If Boy B was doing things with Boy A it "made him a bigger presence", he said, in the absence of the jury.
Dr Humphries said he was struck by how Boy B didn't say anything to him that was threatening or harmful to Boy A. The jury never heard his evidence as Judge McDermott ruled it inadmissible.
The doctor said it was clear Boy B was influenced by Boy A, but that he also hoped it would come to an end.
The boys were friends, though not best friends, but as Boy B told gardaí: "Boy A is not really my friend since what happened."
After he was charged with murder, Boy B spent five weeks in custody in Oberstown Detention Centre before he was granted bail by the High Court. He was the only child in Oberstown to ever ask for Lego, Dr Humphries claimed.
Dr Humphries said Boy B knew he could end up in jail and that terrified him, but he had the "belief the story will get him through". Boy B loved books, and used adventure and fantasy to get away from things, the doctor added.
Prosecution counsel Brendan Grehan said the doctor's evidence should be excluded. He argued Dr Humphries's report contained "lots of jargon" but there didn't appear to be any engagement with the facts of what happened in Boy B's interviews with gardaí.
In his report, Dr Humphries claimed that Boy B had difficulty processing what he had seen. He said the boy had come up with a series of explanations, not intended as lies, but intended to give an account of what happened, while also showing he had no part in it. Boy B was also trying to avoid the memory of what had happened, the doctor said. He said he spoke to Boy B but also looked at the Garda interviews with him. Dr Humphries said Boy B was "very powerless in a very small room with lots of adults".
Mr Justice Paul McDermott ruled the evidence was inadmissible, saying he did not accept the jury required the evidence of a psychologist to understand a 13-year-old could be shocked by witnessing a murder. The judge said the circumstances will be at the forefront of their minds.
In his evidence, Boy B's father said his son liked computer games and anime, a type of Japanese animation series. He did not like anything to do with fights or sports - he had no interest in soccer, his father said - but he liked puzzles, Lego and Transformers.
He is also a chess fan and played chess during any break periods in the course of the trial.
Boy B's father agreed his son also liked making bows and arrows and spears.
His son was happy he was doing something with his hands, rather than sitting in front of a computer, his father added.
In interviews with gardaí, Boy B said that Deadpool was his favourite Marvel character but his friends preferred Thor or the Hulk.
Meanwhile, Boy A loves horror movies, specifically ghost horror movies, and likes drawing, mostly anatomy. He is tall and strong, and trained in martial arts.
Otherwise, the jury did not learn that much about the 14-year-old, who sat quietly at the back of courtroom nine for the past seven weeks.
A questionnaire completed by Boy A where he described himself as "feeling... not much" may give some insight into what he thought of himself.
Boy A said he was "strange" and he thought "differently".
The convicted killer also said he liked to hang out in "abandoned places".
The questionnaire, which was completed by Boy A in February 2018, was ruled as inadmissible as evidence by Mr Justice Paul McDermott who described it as "juvenile jottings".
Boy A said his favourite books were horror, his favourite sport was combat, his favourite movies were horrors and comedies, and his favourite music was rap and heavy metal.
When answering the question are you single or taken, he said he was single.
Describing himself in three words, he said he was "crazy, funny and adventurous".
Boy A also answered; "I am...strange", "I think...differently" and "I feel...not much".
He said he hoped to do well in the future.
The trial was notable in the number of juvenile witnesses who gave evidence, all via videolink.
In his closing speech, Patrick Gageby SC remarked that they seemed like a "very nice bunch of young people".
Prior to giving evidence, the teenagers said they were nervous, and Mr Justice Paul McDermott, like a kindly grandfather, sought to reassure them.
The teens, in their evidence, filled in the jury about some of the goings on in Ana Kriegel's life and in the boys' lives.