When asked if he liked women with black hair after Oswald heard of Levi's attraction to Lacie, Levi admitted to having been attracted to his predecessor as Glen, who was a woman with blonde hair.
Four months after Jack's arrival, the time came for Oswald's final Succession Ceremony. After Levi transferred Jabberwock to Oswald, Lacie's judgement was immediately undertaken. Levi stood by and watched Oswald convict Lacie for her sin of being born with the Red-Eyes of Misfortune. Levi had never told Oswald of how he had impregnated Lacie, so Oswald had no way of knowing that by casting Lacie into the Abyss, he was providing the Core of the Abyss with a vessel as Lacie gave birth in the Abyss.
Levi joined Oswald when Alice was ejected from the Abyss, joining him in greeting her, Levi knowing that Alice was his daughter after learning her name, and because of this, Levi almost seemed to have been distancing himself from Oswald as the next month carried on. Levi eventually died, Oswald still not knowing what his previous master had done, as Levi's soul faded into Oswald's and his body mutated, becoming Humpty Dumpty.
After another 100 years, Levi and Oswald spoke with Leo when Elliot was fatally wounded by Humpty Dumpty in the Hole of Sablier. Oswald spoke in a condescending way to Leo, not offering Leo his sympathy, whilst Levi suggested that Leo have Elliot form an Illegal Contract with Humpty Dumpty in order to seal the wounds for the time being, opposing Oswald. Oswald became silent as Levi said this, showing strain on their relationship because of what Levi was having Leo do. Oswald would remind Leo that Elliot's inescapable demise was his fault because of a distortion around him brought on by his destiny as the successor of Glen Baskerville's soul.
Levi's relationship with Oswald became even more strained when all the Sealing Stones were broken. Oswald gained all the knowledge of what Levi had done with Lacie, understanding finally why everything had turned out the way it had. Levi appeared before Oswald to see him off within Leo's subconscious, but Oswald only glared at Levi, not showing any signs of forgiveness.
Lacie was against this at first, however she complied to Levi's offer for the sake of the Core, wanting to cease its loneliness once and for all. Levi would then make plans to impregnate Lacie when she would come into maturity in the next 10-20 years.
As Lacie matured, her relationship with Levi did as well. Their interactions became much more playful and taunting, allowing Levi to speak to Lacie more as equals rather than as adult and child and following Levi's impregnation of Lacie, Levi started developing feelings for Lacie sooner than he had anticipated. Levi had taken a fast liking to pregnant Lacie, making things slightly more awkward as a result as Lacie was like his daughter and his lover at the same time. Levi also ended up spending more time with her alone as a result of this new found closeness in their relationship. Although Levi had become closer with Lacie, he was still able to be extraordinarily blunt and cold, and yet cheerful, when delivering the news of Lacie's demise to her.
Levi was rather disappointed following Lacie's casting into the Abyss, becoming rather surprised and grateful when Alice was released from the Abyss because he had initially thought that Alice was Lacie, and that she had just been de-aged by the power of the Abyss. However, Levi was ultimately able to accept that Lacie was gone for good.
Also, upon learning the true reason why Jury insisted Lacie being thrown into the Abyss because of her existence as a Child of III Omen, Levi's expression was clearly shocked and horrified, a broken smile on his face. Learning that Lacie's 'fall' was simply because she was a threat to Jury's plans, not to the balance (which, at this point, is more than likely a lie to justify killing Lacie and all the Children of III Omen who came before her.) and that her death was entirely preventable.
Over the course of the next four months, Levi had taken quite the liking to Jack. However, Levi had known that Oswald's final Succession Ceremony was fast approaching, which meant that both his own and Lacie's deaths were fast approaching. Lacie lied to Jack that the Succession Ceremony was in a week rather than in five days, thus allowing Oswald to fully inherit the title of Glen from Levi and allowing Oswald to cast Lacie into the Abyss to be destroyed. Levi sat by and watched when Jack came back to the Baskerville estate two days following the Succession Ceremony looking for Lacie. Levi had hoped that after Jack found out about Lacie's death that Jack would barge into the mansion and demand to see Lacie, however Levi was disappointed and Jack simply returned to the Vessalius estate.
A month later, Levi went to the Vessalius estate on the brink of death, intending to tell Jack the truth about the powers of the Abyss, as well as Alice. In the carriage ride from the Vessalius estate to the Baskerville estate, Levi told Jack of how Oswald had been feeling down because he blamed himself for Lacie's existence as a Child of Ill Omen because of the fact that the distortions created by the vessels of Glen Baskerville are allegedly the cause for such a being's existence. Levi also took the time to explain how Children of Ill Omen are destined to be returned to the Abyss as a way of the Glens cleaning up their messes. The final secret which Levi divulged to Jack in the carriage was about the Chains of the world, explaining to Jack that the Baskervilles protect these Chains because if they should be severed, the world would crumble into the Abyss, trusting that this information was safe with Jack.
When the two reached the Baskerville estate, Levi showed Jack Alice from the bottom of her tower. Jack was shocked by this and Levi explained what exactly Alice was, requesting that Jack take over the experiment which Levi was undergoing in confidence that he would use Alice to fulfill both his and Levi's wishes, as Levi was not going to survive long enough to see the results himself. Since Levi shared all of this with Jack, Levi unintentionally provided Jack with the necessary information to create the Tragedy of Sablier through his misplaced trust of Jack.
Alice was Levi's daughter who had been sent to him through a Door to the Abyss after Lacie had given birth to her and Abyssal power from the Core of the Abyss had accelerated her age by thirteen years. Levi was surprised to see Alice at first, thinking she was Lacie and that she had her age reversed by the Abyss' power, though he soon learned otherwise. Upon meeting his daughter, Levi played along with Alice after she had bitten the black rabbit doll which she emerged from the Abyss with, telling Levi that the doll was awake after all. Despite not understanding Alice's meaning in this, Levi did not question it, and so he welcomed Alice to the Baskerville Dukedom alongside Oswald.
Alice resided in Lacie's old tower after this, Levi now often spending time with his daughter. However, Levi's time with Alice would be cut short now that Oswald had succeeded the title of Glen Baskerville from Levi, speeding the process of Levi's death.
During one of their visits, Levi noticed Alice was drawing her black rabbit, having apparently named it 'Os', and so Levi immediately puts two-and-two together and figures out that she had named the rabbit after Oswald following their interaction. Knowing this, Levi happily corrected Alice's spelling of the rabbit's name to 'Oz', causing Alice to become overly excited, leaving Levi to watch his daughter enjoy herself. As well, because of their interaction, Alice decided to look up 'ore' in a book, because Levi had used 'ore' (as it is a masculine pronoun) when referring to himself, and as a result Alice developed a masculine personality because she lacked a feminine example to draw from.
Soon after their encounter, Levi died, meaning that this short amount of time that Alice spent with her father was some of the only quality time that the two spent together. Levi was shown to truly care for Alice, however he still intended to use her existence for scientific purposes to try and observe whether his experiment had been successful or not. Alice's relationship with her father was somewhat casual, having addressed him by name instead of addressing him as father, possibly suggesting that Levi had never disclosed to Alice that he was in fact her father. Despite appearing to not know in full who Levi really was, Alice seemed to really enjoy Levi's company.
While Alice and her father seemed to have gotten along rather well, her twin sister did not. The Intention of the Abyss had a strained relationship with her father after interacting with him when she switched places with Alice's soul in her body on Earth, her relationship with Oswald was in a similar state.
As the Barmas were exiled from their home country after losing a war, Arthur Barma was known for trying his hardest to get in good with the Baskervilles, being comparable to a lost puppy. Levi saw Arthur in the same way and enjoyed putting Arthur on edge. Though Levi wasn't heartless, so he'd allow Arthur to get close to him, even throwing a party for Arthur on the Baskerville estate as Levi had seen his relationship with Arthur as an opportunity to experience new cultures, which he saw as a valuable and enriching experience.
Despite Arthur trying to get close to 'Glen', Levi's term as the head of the Baskervilles was almost up, and so Levi would soon die and Arthur would have to try to get closer to Levi's successor and former assistant, Oswald.
It is unknown what relationship Levi had with Celia before his 'death' but after he transformed into Humpty Dumpty, Celia contracted with him in order to use Levi's new chain powers to protect Oswald, as the new 'Glen'.