Despite being protective of his son, Gabriel's relationship with Adrien is distant. He and Adrien do not spend time together often, which greatly upsets the latter. He is also very controlling of what Adrien does, having his schedule planned from day to day and not allowing him to go to school without his bodyguard to ensure his safety. However, some if not all of his actions towards Adrien are because he is overprotective.
To some extent, he does openly seem to care for his son, wanting to get him a birthday present in "The Bubbler" despite not choosing it for Adrien himself. In "Simon Says", he shows that he's proud of him by telling Ladybug that he's perfect and a lot like his mother. After being saved by Ladybug and Cat Noir, he finds Adrien in his room and hugs him. When bringing a present to Adrien in "Santa Claws", he panics when he finds that his son isn't in his room and demands that he be found. He's relieved once Adrien returns. As he sadly explains to Adrien, he can't bear to lose him after losing his wife. He also listens to Adrien about allowing a crowd of people into their mansion to celebrate Christmas with them. In "The Collector" he says he views Adrien as one of the few things he has left of his wife after she left, and in "Riposte", when Kagami attacks Adrien, Hawk Moth orders her to stop, and tells her that she can have her revenge later (not actually intending to let her do so), hinting at his care for him even while doing his supervillain work. This is also displayed when he sacrifices victory and proving his theory in "Gorizilla" when he tells the titular villain to drop Ladybug in order to save Adrien, even though he had the opportunity to take her Miraculous. In "Style Queen", he is very regretful of his actions after realizing his son was turned into a golden statue by the titular villain and nearly gives up being Hawk Moth in "Queen Wasp" because of this.
In "Catalyst (Heroes' Day - Part 1)", Gabriel, as Scarlet Moth, shows his concern about Adrien, while creating his army of akumatized villains, by sending Gorizilla to take Adrien and keeping safe him while he completes his plan to get Ladybug and Cat Noir's Miraculouses.
He showed concern for Adrien again in "Startrain", when his out of sight akuma akumatized Max's Mother into the titular villain sending him and his class to space realizing their was nothing he could do. During an alternate future of "Cat Blanc", he heard that Adrien and Marinette was in a relationship and by interfering with that he discovered his son's identity instead of being devastated Gabriel was thrilled he was close to getting what he desired.
Regarding Cat Noir, however, Gabriel despises the hero and intends to take his Miraculous. In episodes like "Dark Cupid", “Princess Fragrance", and "The Puppeteer", Hawk Moth allows Cat Noir to be used indirectly against Ladybug to retrieve her Miraculous. When Gabriel meets Cat Noir in "Simon Says", he isn't pleased when the superhero starts giving orders to protect him; yet when Cat Noir insists more, Gabriel tells him that he is headstrong and that he reminds him of someone, after which he turns to face a portrait of his wife. He shakes hands with Cat Noir after being saved by him and Ladybug. He also notices both Cat Noir's and Adrien's rings and appears to become suspicious.
In "Gorizilla", he does begin to suspect that his son is Cat Noir and acts upon these suspicions by akumatizing Adrien's bodyguard and sending him after him. But after seeing Cat Noir and "Adrien" side-by-side (unaware that the latter was actually Wayhem in disguise), he is fooled by his son's trick and feels relief that Adrien wasn't the hero and his sworn enemy.
In "Mayura", Hawk Moth, despite being an illusion, tries to reason with Cat Noir by saying that his wish would be beneficial to everyone but is aware that he doesn't agree. He also calls Cat Noir an inexperienced hero because he can't stay transformed after using his power.
Saving Nathalie in "Ladybug", he taunts Cat Noir about being sentimental over a sentimonster. When he attempted to take the hero's ring after he captured him the mastermind was unfazed after Cat Noir used Cataclysm because all he had to do wait until they detransformed back. Upon reaching a stalemate, he threw Cat Noir off the building wanting to save Mayura. After the akuma acted on its own during "Startrain" and put his son in danger he hoped Cat Noir could save him. During the "Battle for the Miraculous", after he obtains the Miracle Box, Hawk Moth taunted the heroes attempting to drive them apart but it didn't work. As Hawk Moth in the alternate future he used that knowledge to his advantage calling Cat Noir by his true name. Revealing his identity and the reason for his actions to his son. However being blinded by his negative obsessive feelings on achieving his dream, he made a terrible mistake by breaking Adrien down so much he akumatized him. Resulting in the opposite of what he wanted, his own demise by his son's (albeit accidental) hand. But due to Ladybug fixing her mistake the timeline that involves his death was erased.
Gabriel deeply loved and cared for his wife. According to Adrien in the webisode "Adrien's Double Life", ever since losing her, Gabriel has not been the same. Therefore, he has become obsessed with obtaining Ladybug and Cat Noir's Miraculouses in order to use their absolute power to erase the past event that caused her condition and therefore bring her back. He even keeps an image of her in the Butterfly Miraculous. In "The Collector ", he tells Adrien the Miraculous Spellbook was his last gift from his wife, and he tells Marinette that he got the book while he and his wife were overseas.
Gabriel trusts his personal assistant, Nathalie, to take care of tasks for him and Adrien. He doesn't appreciate when she messes up, however, as when he gets impatient with her when she forgets to get a birthday present to give to Adrien on his behalf. When she gives him useful advice, he listens intently and takes it, as when he agrees with her to let Adrien attend public school in "Stoneheart" and to be there for Adrien on their first Christmas without his wife in "Santa Claws". He trusts her enough that she knows that he is Hawk Moth, explaining his scheme to her about throwing Ladybug and Cat Noir off his trail in "The Collector".
In "Catalyst", Gabriel shows his concern for Nathalie when she recounts his plan to him, asking if she's really okay with helping him, to which Nathalie says that she'll always be there for him. When he akumatizes her, he says that she has always been loyal to him. In "Mayura", Gabriel as Hawk Moth is horrified when Nathalie uses the damaged Peacock Miraculous in an effort to aid him yet reluctantly accepts her help. Later on, when she is fatigued and drained from using it, Gabriel reminds her that he'd told her never to use the Peacock Miraculous as it is damaged and far too dangerous, yet he is still grateful when Nathalie says that she wanted to help him no matter what.
Gabriel views Nooroo, his kwami, as nothing more than his slave. After Gabriel proclaims that he intends to use the Butterfly Miraculous' power to create supervillains instead of superheroes, Nooroo attempts to tell him that the Miraculous aren't supposed to be used for evil, but he refuses to listen. He yells at Nooroo, reminds him that he is his master now, and demands his obedience.
In "Syren", feeling that his kwami was hiding secrets from him, Gabriel interrogated Nooroo on how he could get more powers. Figuring that the recipes were in the Spellbook, he asked the kwami if he could read it. But all Nooroo said was that kwamis don't know the recipes and only a guardian can decipher the codes in the book.
As revealed in "Sandboy", Gabriel does not allow Nooroo to be more than a few feet away from him or to communicate with anyone besides him. Even on his birthday, Gabriel refuses to let him go out and even momentarily seals his mouth shut as a "joke". After receiving the kwamis' communication, Gabriel tells Nooroo that he hopes he likes his friends' birthday gift, as now he knows that they're close and numerous and vows to capture them all.
Gabriel recognizes Marinette as a skilled hat maker and lets her prove that her hat is her own creation in the contest he was judging. When she does, he compliments her hat and declares her the winner. He treats her coolly in "The Collector" when she visits him and returns the Miraculous spellbook to him, and accepts her request by letting Adrien go back to school again. In “Frightningale”, he believes that Marinette would be a good choice to play Ladybug in Clara Nightingale’s music video. In "Queen Wasp", he comments on Marinette's talent when Audrey Bourgeois takes a liking to the derby hat she created.
Despite this, he doesn’t actually care that much for Marinette personally. As Hawk Moth, he has no remorse when his akumatized villains attack her and has no problem with trying to akumatize her in “Zombizou” and “Chameleon”.
In “Ladybug”, knowing how well-liked Marinette is by her classmates, he allows Lila to sabotage her in order to bring her down and make her and her friends vulnerable for akumatization. He actually does succeed in akumatizing her, but he doesn’t get to complete the transformation as Nathalie’s health issues take over. During an alternate future in "Cat Blanc", he heard that Marinette was in a relationship with his son and approached her demanding that it ends to preserve his company's image. Aware of that he uses her feelings for him against her by pulling Adrien out of school and she tearfully agrees to his demands. Sensing Marinette's utter despair he attempts to akumatize her again but was stopped by his son.
Rearding Ladybug, Gabriel wants nothing more than to defeat her, take her Miraculous, and make her suffer once he wins. While he despises both Ladybug and Cat Noir and wants both of their Miraculous, he seems to blame Ladybug more when he fails and feels more aggression towards her. The reason is unknown, but it is most likely because she is the only one who can capture the akumas he creates and turns them back to normal. He pretends to respect her, acting as if he trusts her to protect him and chatting with her about Adrien when she and Cat Noir are guarding him in "Simon Says". He also doesn't hide his interest in her earrings. Under the threat that his identity would be exposed in "The Collector", he threw Ladybug off his trail by akumatizing himself, fooling her into thinking Hawk Moth was someone else. However, despite his deep dislike of her, when he saw that Adrien wasn't going survive the jump in "Gorizilla", Gabriel as Hawk Moth knew that Ladybug was the only one who can save him, so he commanded the titular villain to let her go so she could do it. In "Mayura", Hawk Moth, despite being an illusion, tries to reason with the hero by saying that his wish would be beneficial to everyone but is aware that she doesn't agree. He also calls Ladybug an inexperienced hero because she can't stay transformed after using her power.
In "Ladybug", he meets Ladybug again and upon seeing that she caught Mayura while he caught Cat Noir; Hawk Moth demanded the heroine to let her go upon reaching a stalemate. Realizing that Mayura was more important he let Ladybug save her partner. After the akuma acted on its own during "Startrain" and putting his son in danger he hoped Ladybug could save him. During the "Battle for the Miraculous", after he obtains the Miracle Box, Hawk Moth taunted the heroes (especially Ladybug over her mistake) attempting to drive them apart but it didn't work. While dealing with her alter ego in an alternate future of "Cat Blanc", he unveils his identity and reasons to her and like before he tried to use their love for each other against them but it resulted in their demise. But thanks to Ladybug fixing her mistake in the past the future of demise was erased.
The only purpose Hawk Moth has in creating akumatized villains is that he needs them to retrieve Ladybug and Cat Noir's Miraculouses from them. He pretends to be a caring friend, promising to assist them with their frustrations by giving them powers, just as long as they return the favor by retrieving the Miraculouses. If necessary, he will lie to them as well, such as telling them the superheroes are being dishonest. He often stays involved with what they're doing, and he'll give advice or plans to them in some situations.
However, if an akumatized villain doesn't follow through with obtaining the Miraculouses, Hawk Moth gets furious. He becomes frustrated when The Bubbler kicks a bubble that holds Ladybug and Cat Noir into the sky without getting their Miraculouses, and when the Evillustrator avoids his responsibility, preferring to prepare for a date with Marinette, he temporarily controls the villain's body to urge him to carry out his primary task. He does the same thing to Pixelator when he says he doesn't have time to chase Ladybug and is more interested in getting a photo shoot of Jagged Stone. Hawk Moth even threatens to remove Dark Cupid's powers in the episode of the same name if he doesn't bring him Ladybug's Miraculous.
Noteworthy occasions when he has a different relationships with his victims include Manon/The Puppeteer, to whom he shows more kindness, even sometimes praising her; Markov/Robostus, who becomes his adversary in obtaining the Miraculouses and attacks him; August/Gigantitan, who due to his young age is unable to follow his commands; and Adrien's bodyguard/Gorizilla, whom he simply uses for his own agenda.
Gabriel seems to like Lila to some extent as she shares the same hatred for Ladybug that he has. In "Catalyst", he ensures that she will be angry enough to be prone to akumatization by insulting her akumatized identity in a TV interview. In "Chameleon", he delightfully agrees to her request to akumatize her. However, he is unhappy to see her in his home in "Oni-Chan", even sending an akumatized villain after her to keep her away from his son. But when Lila makes a deal with the akumatized villain that she'll renounce Adrien in exchange for having Ladybug defeated, Gabriel as Hawk Moth is impressed and later concludes that he was wrong to try to push her away, as she would make a great ally. He invites her to his home the next day and although he does expresses scorn over the fact that she previously came into his house through lies and manipulation, he forms somewhat of an alliance with her despite not revealing to her that he's Hawk Moth. From that point on, he manipulates her into helping him as Hawk Moth by pretending to trust her in protecting Adrien.
Gabriel has a strong distaste for Nino and believes that Nino is a bad influence on Adrien. When Nino objects to him not allowing Adrien to have a birthday party in "The Bubbler," Gabriel, displeased with his authority and decisions being questioned, tells Nino that he is not allowed in the mansion anymore because he is a bad influence on his son. However, in "Simon Says", he appears to have either forgotten about this or gotten over it, as he hardly acknowledges his presence inside the mansion.
Gabriel is aware of Carapace's existence but is unaware that he is Nino. He as Hawk Moth battles him along with the rest of the French Miraculous superhero team during Heroes Day.
While Gabriel doesn't care much for Chloé, he acknowledges in "Despair Bear" that he relies on Chloé's cruelty and nastiness to make people emotionally vulnerable enough to be akumatized, so much so that he sends out an akuma ahead of an opportune victim when she holds a huge party.
In "Queen Wasp", he is very surprised when he discovers that she has the Bee Miraculous in her possession and is inspired to continue being Hawk Moth because of her. During "Heroes Day", he battles her along with the rest of the French Miraculous superhero team and has no qualms about akumatizing her family and butler in order to distract her.
In “Miraculer”, he expresses a desire to have Chloé become Queen Bee again and join his side. Though his plan ultimately fails, he senses that Chloé’s faith in Ladybug has diminished to some extent and is confident that she’ll change her mind.
Though Gabriel has never met Alya personally, he is aware of the existence of her alter ego Rena Rouge and is surprised that a new hero is in Paris when she first appears. He as Hawk Moth battles her along with the rest of the French Miraculous superhero team during Heroes Day.