Vaughn was one of the first people that Elles met when arriving in Nyvoll, and Vaughn very quickly earned Elles' respect. Even though it's only been a couple days, Elles feels like he can trust and depend on Vaughn, no matter what.
Drew is a bit of a wacko, but goddamn he's endearing. After living with him for a few days in Nyvoll and now living in the NHR base with him, he's become one of Elles' more trusted friends, alongside Vaughn and James.
Elles would die for Cheryl, to be quite honest. She gave him a job and some amount of stability when he most needed it. It's hard to get anyone more trustworthy than that in an apocalypse.
Asterin was the first non-infected person that Elles met upon arriving in the general Nyheim area. He knows she can handle herself in a tense situation, but it's clear that her emotions can overwhelm her sometimes. Elles almost views himself as her older brother.
James was the second person that Elles met in Nyvoll, and he's had a few run-ins with him since. Elles has figured out that James is a good person, and he knows he can always count on him.
Rok seems easygoing and friendly, and he also happens to be good with a gun. Elles likes him and has not been given any reason not to.
Elles trusts Nat, but he also recognizes a darker side to her. He hopes to get to know her better, and he can't deny the definite crush he has on her... unless anyone asks, in which he vehemently denies it.
Sofiya was one of the first people that Elles met upon entering Nyheim, and she has been really nice, despite some angrier cohorts. They survived a bear attack together, so it's hard for Elles to dislike her.