Rollan and Essix are both loners at heart, and from the start, Essix wouldn't listen to most of her summoner's commands. However, Essix would not abandon him in times of danger and stays close to him when it is necessary, showing that she cares about him. She seems to like giving Rollan a hard time, but does so affectionately. She also enhances Rollan's vision and intuition when close. While traveling through Arctica in Fire and Ice, Essix steals a piece of jerky from Rollan's hands and feeds it to him like he was a baby bird. Rollan often longs to be physically close to Essix throughout this book, but respects that his spirit animal is independent by nature. When the group frees Suka, Essix is transformed into Great Essix with a talisman and carries Rollan through the air. During that time they grow a closer bond, and by the end of the book, Essix finally adopts her dormant form; a tattoo over his heart.
At first, Rollan and Meilin clashed, because they have different morals and senses of duty. They get into arguments frequently, but occasionally they would both show signs of caring for the other (such as when Meilin sleepwalks in Hunted, and Conor sees that Rollan has a concerned look on his face but quickly changes it to a smirk.) Rollan described her as the "snotty general's daughter", but enjoys getting a smile or even laugh out of her. They create their own inside joke about tutors in Zhong by teasing each other. Throughout the series, they learn to trust and care deeply for each other (the fact that they also have romantic feelings for each other becomes quite obvious). After General Teng dies, Meilin realizes that she was more like Rollan than she ever thought possible, and even admits that he would smile his 'Rollan smile' that she was coming to know so well. While attempting to calm Suka in Fire and Ice, they hold hands for the first time, and during their trip to Nightshade Island in Against the Tide, Rollan holds Meilin's hand twice as a source of comfort (to which Meilin feels the same). As Gerathon takes control of Meilin's mind and forces her to betray the Greencloaks, Rollan is devastated when he realizes what is happening to her, and angry that somebody gave her the Bile. Throughout Rise and Fall and The Evertree, they both miss and worry about each other greatly and when Meilin is cured of the Bile's poisoning and reunited with the group, Rollan hugs then kisses her, causing Meilin to become shy. Rollan admits that it seemed like the natural thing to do. Many other characters are aware of Rollan and Meilin's feelings for each other, such as Abeke, Xue, and Shane, and the two are often teased about it. They will both become embarrassed if the subject is brought up. In The Burning Tide, when they are still far apart from each other, after communicating through Mulop, Rollan plans to ask something about Meilin when they have to leave and Shane refers Meilin as his girlfriend, to which Rollan denies it. They will both become flustered if the subject is brought up. In Heart of the Land, chapter 16: Sneak Attack, Meilin and Rollan were about to kiss when a shrill scream came from the camp ruining the moment. In Stormspeaker, Rollan and Meilin share multiple kisses, as well as Meilin experiencing jealousy toward Jehan
Rollan seems to be comfortable with Conor around and refers to him as his best friend. Conor warms up to Rollan quite easily in the first book. He states in Immortal Guardians that Rollan never failed to make him feel loved. In Hunted, Conor gets flustered when Rollan points out that he looked decent in a kilt. In Blood Ties, though, Rollan gets angry at him for giving away the Iron Boar and causing Meilin to return to Zhong. While walking through a swamp, he falls into the mud, but Conor pulls him out from behind. Rollan thinks that he should thank him, but everything was "too raw and complicated". Throughout the book, he is still mad at him, despite Conor's desperate attempts to mend their friendship. During a battle with the Conquerors, Rollan looks to him and says "Together, right?" and Conor replies "Always." In the next book, Rollan finally apologizes to him and they become friends again, as Rollan's meeting with his own mother made him able to relate to Conor's dilemma. Rollan often makes jokes about how Conor smells bad, gives him the nickname 'Sheep boy' and dares him lick the ice that Suka was frozen in. In Against the Tide, when Conor was temporarily stuck underwater while Meilin betrayed the Greencloaks, Rollan was worried that he'd lose Conor as well as Meilin. In Rise and Fall, Rollan tells Conor that he liked his old "sheep boy" self better, but Conor tells him that he's gone now.
Aidana is Rollan's mother, as revealed in Fire and Ice. When he was a baby, Aidana was afflicted by the bonding sickness and sometimes unintentionally hurt him, not knowing that she did. She reveals that once she almost killed him, thinking in her delirium he was a rat attacking her while she was sleeping. After that she knew Rollan couldn't stay with her; so she set him at the doorstep of a big house in the middle of town (that she had been watching the family of), knocked on the door, and ran. The family did not take Rollan in, but Aidana didn't know that, and Rollan never told her. She explains to him that she was just about dead because of the sickness when Zerif found her and gave her the Bile, curing her. So she joined the Conquerors, and after, went back to the house, just to be met with a different family; the old one had moved out. After their reunion, Rollan leaves her to 'check on his team'. The next day, he makes the decision to leave Samis before Aidana and the rest of the Conquerors could know. At the end of the book, Rollan and Aidana leave in the middle of a battle and by then, Rollan knew something was wrong with his mother. She attacks him, her eyes turning into snake eyes as her mind is taken control by Gerathon. She whispers to Rollan to kill her before he gets away and runs. As the Greencloaks are sailing away, Rollan is heartbroken by the fact that he was forced to lose his mother once again.
They do later meet again in The Evertree, where Aidana is freed from the bonding sickness due to Gerathon's death. She is also introduced to Meilin.
Rollan sees Tarik as his father figure and guardian. They both trust each other completely. In Rise and Fall, when Tarik is fatally injured by Gerathon he tells Rollan to take his green cloak and run, and then dies, leaving Rollan grief-stricken. It was because of Tarik's death that Rollan decides to become a Greencloak. Rollan wears Tarik's cloak and is often reluctant to take it off.
Tarik's death still shakes and upsets Rollan deeply, to the point where even mentioning it makes him become emotional. In The Evertree, he asks Meilin if she thought Tarik would be proud of him, to which she replies that he would.
Like the other Four Fallen kids, Rollan trusts Abeke immensely. Although he didn't trust her at first because of her time with the Conquerors, he confided in her about his Nectar Ceremony and his encounter with Zerif. She was the first person that he un-jokingly told about his ceremony. They both also seem to know that they have to make use of everything they have, especially food. In The Evertree, Rollan told Abeke that Shane's betrayal was not her fault. She thanks him, and they have a moment of joking. Abeke isn't amused by Rollan's uplifting jokes sometimes, but she seems to appreciate the sentiment. When the Greencloaks on the Tellun's Pride were forced to abandon ship and jump into the ocean, Rollan uses the Coral Octopus to swim over to Abeke, grab hold of her, and swim to shore. In Broken Ground, Rollan witnesses the friendship between Nisha and Arac and wonders if he and Abeke will be like that when they are older. Abeke mentions during the book that Rollan surprises her sometimes with his streaks of kindness.
When Rollan, Meilin, and Tarik sail to Nightshade Island (an island that Kalani's people consider "tabu" or cursed), Kalani avoids them when they return because of her people's belief. In The Evertree, Kalani still avoids and tries not to acknowledge Rollan. Rollan confronts her about it, telling her that they couldn't get through this journey without trusting each other. Kalani finally starts to talk to him again, and Rollan is the first person she told about the poisonous Stetriolan waters and that it was making the rockback whales, who were pulling their ship, sick.
Rollan, like the other Four Fallen kids, are not very fond of Shane. Rollan is the one to accuse Shane of lying about his spirit animal, which he and Conor found dead in Nilo. In The Burning Tide, they are still tense around each other, but Shane is able to combat Rollan's sarcasm with his own, which seems to make Rollan respect him more. Shane even smiles when Rollan makes a joke about him wanting to get the Greencloaks 'out of his hair'.