Although some people are afraid of and slightly wary of Harvar due to his personality, he still gets along well with his friends as they all know that deep down, he is still a reliable and dependable friend. He is also considered one of the elites of the Shibusen due to his grades and ability.
Harvar has shown to be extremely protective and loyal to his partner Ox. He claims that he has a duty to protect his Meister, and Harvar is willing to do anything, whether it be risking his life or attacking even a former comrade, to ensure his safety. However, Harvar also respects Ox's judgment, and follows any of his commands, even if it goes against his own wishes. Although at first his protectiveness over Ox seems to stem from a strong sense of duty, it is seen that Harvar does care for Ox as a friend, referring to him with the friendly suffix 'kun.' He understands Ox's feelings for Kim quite well and supports him along with Kirikou, and also seems to comprehend Ox's eccentricity (such as his hairstyle). The two seem to get along well and share the same hobby, with the only recognizable strife between them being Harvar's brutal and no-nonsense personality.
Harvar has limited interaction with Kilikg Rung, but like Ox, probably disapproves some of his hotheaded methods of solving things. However, he is aware that Kirikou is a kind and dependable friend, and when Kirikou lets he and Ox go to search for Kim in Baba Yaga's Castle, Harvar comments, 'He's a nice person, isn't he Ox?' Yet Harvar agrees with Ox that Kilik's boisterous encouragement that they find Kim and Jacqueline inside Baba Yaga Castle is a bit too distracting when they are all supposed to be undercover as members of Arachnophobia
Harvar does not seem to feel much for the small twin Weapons, not even attempting to hide his brutality in front of them, which consequently makes the two fear him.
While Tsubaki is babysitting Fire and Thunder, Harvar sits back, not participating in their games with Angela Leon.
Harvar understands Ox's feelings for Kim, and thus sees her as a friend and colleague, although their relationship is strained upon learning of her identity as a witch, by her defection to Arachnophobia, by her attempt to kill Ox when brainwashed by the Morality Manipulation Machine, and by her disagreement with him regarding Death's orders to assassinate Crona. For her part, Kim regards Harvar as a bit of a "hard-ass."
Upon learning that Kim is a witch, Harvar's hatred for witches leads him to treat Kim as no more than an enemy. Even as he accompanies Ox to retrieve Kim and Jacqueline O'Lantern Dupré from Baba Yaga Castle and back to Shibusen, upon witnessing Kim and Jacqueline almost kill Ox in combat, Harvar does not even think that the two are brainwashed, arguing that Kim must have been deceiving Ox from the very start, as he expects a witch would.
Despite Harvar's willingness to kill Kim in combat at Baba Yaga Castle, stabbing her with his spear, after Kim is freed from her mind control and accepted back into Shibusen, Harvar accepts her as well, which implies that their friendship is more or less re-established.
Despite being colleagues in Spartoi who share missions, Kim and Harvar, like almost any teammates, do disagree strongly with each other on important point. For example, Kim is one of the members of Spartoi to question Death's orders to assassinate Crona. While Kim sympathizes with Crona as she herself feels the same fear that one day Shibusen will order her capture, or worse, because she is a witch, Harvar reasons that Death's orders are infallible. Therefore, Kim does consider Harvar to be a "hard-ass" and attempts to convince Harvar's meister, Ox, to side with her, pointing out that she as a witch is also under threat of capture by Shibusen.
Much like Kim, Harvar treats Jacqueline as evil as soon as she and Kim attack Ox and him in Baba Yaga's Castle. However, Harvar seems to show a bit more mercy to Jacqueline despite this, as he gives Jacqueline the opportunity to surrender after 'killing' Kim. He still does not hold back though when Jacqueline continues to fight after Kim returns to normal, although arguably, he only knocks her unconscious this time, and even carries her back to the Moral Manipulation Machine to return her to normal, showing that he at least senses that Jacqueline is a friend.
Harvar expresses a dislike towards Black Star, which is not much of a surprise due to their completely different personalities and contrasting thoughts.
Whereas many of his peers, even Death's own son Kid, are willing to question the shinigami's orders, Harvar seems to be a stricter adherent, although not without rationalizing his decision to follow Death's orders. As he tells Kim Diehl regarding their mission to assassinate Crona, Harvar responds that, while Death's judgments are not infallible, those decisions are the laws of an absolute being. "The cycle of life and death rules all beings," Harvar concludes, so they too must follow the rules of Death: "That's just how the system works."
Although a friend of his Spartoi colleague Maka Albarn, Harvar thinks that Death's order to execute Crona takes priority. Therefore, Harvar seems to regard Crona as an enemy only: any interaction between Harvar and Crona in their classes at Shibusen is not yet apparent.
When Eruka is captured by Black Star and brought to Death to provide a magical entrance for Spartoi into the Book of Eibon, Harvar seems to delight in toying with Eruka's fear of what Shibusen could do to harm her. Whereas his meister Ox focuses on directions to Eruka with no obvious malice towards her, Harvar, smirking, reminds the witch that the captive collar around her neck has explosives that, should they deem it necessary, they will detonate to hurt, if not kill, her.
For her part, Eruka seems to recognize that she is not in a position to talk back at Harvar and other members of Shibusen, which means she channels that frustration by taking it out on Shibusen's witch allies such as Kim Diehl, Risa, and Arisa, whom she calls idiots.