Oswald had been born with a distortion around himself generated by his connection to the Abyss. This distortion often caused unhappiness in the lives of the people around him, and because of this distortion, his younger sister, Lacie, had been born as a Child of Ill Omen.
Oswald was accepted by the power of the Abyss while still very young, and so as he was drawn to his new master, Oswald and Lacie set out together. They arrived at a mansion in the centre of Sablier, where Oswald was decided to be the successor of the current Glen Baskerville, Levi. Lacie too was allowed to live as a Baskerville, destined to one day be returned to the darkness of the Abyss by her own brother because of her sinful existence.
Oswald and Lacie were traversing the lower levels of the mansion one day when they encountered an elderly woman. This woman called Children of Ill Omen abominations and questioned why there was one living in the mansion, ordering Lacie to fall immediately. Oswald called to his younger sister to join him, while Levi asks the woman not to scare Oswald and Lacie like that as they were new inductions to the Baskerville Dukedom. The woman asked if Oswald was meant to be Glen's next vessel, which Levi confirms, explaining that he was making preparations for the first Succession Ceremony where he'd transfer Raven to Oswald, following this would be Owl, Dodo, Gryphon and Jabberwock. However, Levi explains to the elderly woman that the process could take anywhere from 10 - 20 years, meaning that she would just have to bear with Lacie's existance for the time being.
Levi then leaves with Lacie and Oswald and Lacie asks Levi who the woman had been. Levi explains that she was Jury, meaning 'the lurking eyes'. Lacie asks if she was a Baskerville, which Levi confirms, stating that he duties as a Baskerville differed from the rest of them, as her main purpose was to protect the head of the Baskerville Clan. Oswald asks why Levi needed to be protected, and Levi says that it was just the way things were, and that instead of them wondering why Jury existed, they'd be better to ask themselves what they'd do about it, either that or accept it as it was. Lacie recalls how Jury had told her to fall, and so she asks Levi if she was going somewhere, and Levi explains that Lacie would be returned to the darkness of the Abyss when the time came. Lacie asked what would happen to her when this came about, and so Levi cheerfully states that Lacie would die.
Oswald had gotten into a disagreement with Lacie many years later (around the age of 15) and so, Lacie ran away from the Baskerville estate, refusing to return unless Oswald apologized. Oswald sent out several Baskervilles to search for Lacie, extending his deepest apologies to her so that she would return home.
Another eight years later, Oswald had successfully inherited Levi's Chains, Raven, Owl, Dodo and Gryphon with the final Succession Ceremony on the horizon. Oswald was now Levi's personal assistant, screening all whom he encountered on Levi's behalf. On the day of an event held by Levi in Arthur Barma's honour, Oswald encounters Arthur's musician, who was disguised and wielding only a morin khuur from the Barmas' culture. Oswald knew that the musician was Jack Vessalius and although he thought that he was suspicious, Oswald still permitted his entry into the Baskerville mansion because Levi had told him that he relies too much on his instinct, allow Jack a chance to prove himself.
Jack however proved Oswald's instinct right when he threw down his costume and morin khuur in order to embrace Lacie as she arrives at the event. Oswald runs up to Jack and uses a knife to knock Jack unconscious. Levi asks Oswald not to kill Jack, also asking Arthur what he'd known about him. Although Arthur states that his sister had merely introduced him to Jack, Oswald asks Lacie if she had known him. Lacie looks at Jack's single earring and recognizes it as one she'd given to a boy eight years before, however claiming not to know him.
Levi has Oswald bring Jack to his study and gather information about Jack. Oswald immediately tells Levi that the man was Jack Vessalius, 23, third son of Viscount Vessalius. Levi remarks on how fast Oswald had gathered that information, but Oswald explains that he'd already known it because he'd seen Jack at social gatherings before. Levi asks Oswald why he'd let Jack into the mansion, as everything about him looked suspicious. Oswald explains that he was trying not to rely on his instincts as much, like Levi had told him, and for this Levi tells Oswald he's a complete idiot.
Jack asks suddenly if he could see Lacie, which makes Levi smile and ask if Jack knew where he was. Jack explains that he was in the Baskerville mansion, although Levi tells him that this wasn't quite right, explaining that he had absolute power as the head of the house, and could have Jack tortured to death if he wanted, and nobody would object to it. Jack asks Levi to see Lacie one last time if Levi intended to kill him. This makes Levi laugh and state that he didn't know what happened between Jack and Lacie before, but that she often escaped the mansion and searched for a 'pet' to dote on for the day. Jack explains that he knew Lacie had forgotten him and that he was glad to see that she hadn't changed a bit. Levi finds Jack to be odd, not being able to recollect Jack in his mental who's-who of the noble families. Oswald tells Levi that it was because Jack was only recently allowed to be seen within social events, as he had been born of a mistress of Viscount Vessalius' and had lived with he for most of his life in a backwater town.
Levi asks how Oswald knew all this, and so Oswald explains that he'd done some research on Jack. Levi smirks and removes Oswald's hood, revealing him to Jack. His appearance surprises Jack and so Jack asks if they'd met at a ball or something of the like before. Oswald explains that they hadn't, this being heir first meeting face-to-face, however it was his job to keep watch of everyone of importance. Levi notes that it was still unusual for Oswald to show such an interest in someone, which Oswald agrees with, stating that he couldn't help but be interested in Jack. Levi is surprised, as he didn't realize that Oswald 'swung that way', although Oswald didn't understand what Levi meant by this, continuing to explain how he couldn't help but wonder why upon first seeing Jack, he made Oswald's skin crawl. Levi laughs hysterically, and Oswald asks what Levi's laughing about, prompting Levi to ask if Oswald even heard himself speak. Levi then asks Oswald to try and explain what he felt for Jack. Oswald explains that it wasn't easy to put into words, however Levi continues to urge Oswald to try.
Oswald stated that Jack felt like water to him, like a stretch of water so silent and still that even fish avoided it, and when you look into it, you can only see your own reflection rather than Jack's true nature. Oswald states that even though Jack was infront of him, he couldn't shake the feeling that no one was actually there. Jack, embarrassed, throws water on Oswald. Lacie scurried in, grabbing Jack and dragging him out of the room, leaving Levi to laugh hysterically.
Later, another Baskerville is questioning Oswald outside about what had happened, when Oswald tells him that neither the Barmas or the Vessaliuses would be held responsible for what had happened at the event. Oswald then turns to see Jack with Lacie, smiling warmly at Jack before carrying on.
Jack frequently visited the Baskerville mansion in the following months (having been given a map of the mansion by Levi), on one particular day, Jack sits with Lacie and Oswald near Lacie's tower, Lacie singing her song. Jack notes how it was the same song Lacie had sung eight years ago, asking the name of the song. Lacie explains that Jack should ask Oswald, as Oswald had composed it, while she only added the lyrics. Oswald is silent with embarrassment over the fact that Jack knows that he'd composed the songs, but Oswald explains that he'd never thought of a name, although Jack could name it if he pleased. Jack suggests 'Lacie' immediately, which suprises Oswald, but Jack explains that to him, the song embodies everything that Lacie was, asking Lacie herself if it was all right to name the song after her. Lacie simply says that if it was all right with Oswald, she didn't have a problem with it. Lacie abruptly turns away from Jack, making an annoyed face, which Oswald sees and grows concerned about. Jack then thanks Lacie for allowing him to name the song after her.
Jack once again arrives at the Baskerville's estate four months after his reunion with Lacie, where he meets with Oswald again, coincidentally having fallen within some bushes trying to get in. Lacie and Levi note from their view of them walking in together that even though Oswald is said to "despise" Jack, he had taken a high interest in him which baffeled the likes of Glen. Lacie explains that Jack is afraid of Oswald because of the way hestares at him, leaving him feeling exposed. In Lacie's opinion, the two had already become extremely close friends.
Jack notices something different about Oswald and asks if something had happened to him, Oswald turns tensely, though he asks him why he asked. Jack says that he looks more serious then usual, at which point Oswald starts feeling up his face, trying to get rid of the tension. He turns suddenly to a confused Jack, staring at him again, though all he recieves is his friend's gentle smile. He shakes it off, though frustrated at his attempt to see Jack, and then asked after a minute of quiet if that was all Jack was wondering, startling his friend with the sudden question.
Oswald then lists what he believes is also on Jack's mind: 'What exactly were the Baskervilles? Why is there an isolated tower where Lacie is held on the estate? How suspicious is all that's going on around them really?' Yet it confused Oswald as to why Jack came to the mansion as if none of that bothered him without even having these questions answered.
Later Jack and Lacie are discussing what is to happen, since she had told him he couldn't visit for a while. Lacie explains that Oswald is going to become the Head of the Baskerville Dukedom now (Levi would finally transfer Jabberwock, Oswald drinking a combination of Jabberwock and Levi's blood during the transfer ceremony), and as such the Ceremony would complete itself after a week. Lacie herself was meant to be a part of the Ceremony that would take place in five days time (where she, as a Child of Ill Omen would 'fall' into the depths of the Abyss and be destroyed). In an earlier conversation between Glen and Lacie, it is realized by Lacie that Oswald, as Glen, would be the one to use one of the Five Black Winged Chains to kill his her, which Glen confirmed.
When Jack once again returns to the Baskerville estate a week later, Oswald tells him that Lacie had died and that he was the one to kill her. Jack had to be told several times before her understood, and Oswald delivered Lacie's earring to Jack as he'd been wearing her other one for the past eight years.
Jack somehow ended up back at the Vessalius estate after his encounter with Oswald, which is where he remained for a month before Levi came to retrieve him. Levi reveals that Oswald blames himself for Lacie's death and is finding it hard to deal with. Oswald is shown back at the mansion, noticing the time, and then proceeding down the hall until he sees a hallucination of Lacie. This distracts him, and his runs into one of his suboordinates, Charlotte. Charlotte barks at Oswald to watch where he was going before realizing who he was, Lottie then proceeded to stand, bow and wipe he lipstick off of his jacket before running off embarrassed. Oswald was stunned and wonders if Charlotte was new to the Dukedom, as he hadn't seen her before.
On his way to Lacie's tower, Oswald remembers casting Lacie into the Abyss, and how he'd had trouble doing so at first. Lacie asked him what was wrong and told him to finish it, which he did, his Chains summoned their chains of conviction to drag Lacie down into the Abyss, but before Lacie submerged, she told Oswald something that shocked him. She was then dragged down into the Abyss smiling.
Oswald then continues to proceed to Lacie's old tower with a picnic basket. As he ascends the tower, he finds the nostalgia of Lacie to be hard to deal with. When he reaches Lacie's old room he greets Alice, a girl who looks like a younger Lacie. Oswald asks if it was her today, and Alice confirms this, saying that she took the opportunity to switch out with the Alice who hated Oswald. Oswald then complains about the way Alice speaks, and tells her to stop talking like a tomboy, Alice tells him that she'd stop when he did and that he was setting a bad example. Oswald then shows Alice that he'd brought her some food, making her ecstatic, especially when she discovered that it was meat. Levi reveals to Jack that Oswald had taken it upon himself to take care of Alice, because of what had happened to Lacie. Levi also explained how Alice was his and Lacie's child and that she'd been born in the Abyss, being spat out after getting aged because of the Abyss' time distortion abilities. Levi explains that he wanted to see how the Baskervilles would react to such changes as providing The Core of the Abyss with a vessel, but that he'd be unable to see it before his death. Levi asks Jack to take over the experiment and tells him that he can use Alice for his own wish if he so desired, before disappearing.
Jack then approached Oswald when he was sitting by a small pond just outside of Alice's tower. Oswald had thought that Jack killed himself after Lacie's death and was surprised by Jack's sudden appearence. Jack reaches a hand out to Oswald to help him up, and asks that they go and bring Lacie back together.
Another flashback shows that after trying to help Oswald up, Jack climbed up a tree just outside of Alice's tower. Oswald asks what Jack thought he was doing, and Jack explains that because Oswald won't let him into the tower, he'd just have to climb up through Alice's window instead. Oswald shows concern for if Jack fell, and Jack explains that he didn't have a choice as Oswald wouldn't tell him anything about Alice. Jack fell from the tree and Alice ran to the window, asking who Jack was. Oswald asks Jack how much Levi told him about Alice, and Jack lies saying that he didn't know anything, that Levi had just shown her to him from the bottom of the tower. Jack then added that he didn't even know her name, though he'd like Oswald to tell him, and Oswald does.
Jack explains that he wasn't doing to ask why Lacie disappeared or what Alice was, but that he just wanted to help Oswald watch over her, as he wants to be close to the only piece of Lacie he had left. Jack pieces together that Levi didn't tell Oswald about his experiment, and so Jack would use his friendship with Oswald to obtain information about the Abyss in hopes of bringing Lacie back to him.
It is later revealed that Oz was named after Alice's encounter with Oswald, though she'd originally called Oz by 'Os', Levi came along and corrected the name for her.
During the Tragedy of Sablier, Oz if forced to see Oswald and Jack fighting. Oswald asks Jack to stop and lay down his sword, Jack explains that he never wanted to hurt anyone like this (as he'd just threatened to kill Gilbert) Oswald attacked with supernatural speed, though when he reached Jack, chains from the Abyss sliced through his body. Oswald asks about Jack's Chain that he'd used to attack him, and Jack introduces him as Oz the B-Rabbit. This shocks Oz, who questions why Jack would call B-Rabbit by his name. After hearing the Chain's name, Oswald understood, Jack had used it to break the chains despite knowing what would happen as the result. Oz tries to piece together what's going on, as Alice was the B-Rabbit and he was her contractor. Just then Baskervilles in the memory come to Oswald's aid, Jack simply calls for his Chain, and although Oz tries to stop B-Rabbit from killing, it massacres the Baskervilles anyway. Oz starts to realize that it was him who destroyed everything 100 years ago, though soon he sees a memory of Alice who asks him to come save her whenever she's hurt. Oz then sees his true form, the form of Alice's black rabbit doll.
After Oz has come to the realization that he is in fact B-Rabbit, he remembers his creation 100 years ago. Lacie had provided The Core with a friend by leaving one black rabbit doll in the Abyss and keeping one for herself, they were both connected and developed one consciousness between the two bodies as one existed in the Abyss. Lacie left both rabbit dolls in the Abyss when the time came for her to die and so it fell into a deep sleep. After Lacie gave birth and her children were caught in paradoxes, one Alice grabbed a rabbit and traveled to Lacie's world, whilst the other grabbed a rabbit and remained in the Abyss where she became the vessel of The Core.
Gilbert and Oswald sense it when the doors to the Abyss open. Oswald immediately gathers the Baskervilles and orders them to kill everyone in the castle, and that it didn't matter if they were women or children, but that they all had to be killed. After Jack used Oz to cut the chains holding this world away from the Abyss, Oswald appears to know that this has happened, as he sends all five of his Chains to have their power stop the chains from crumbling any further. Jack confronted him and asked him why he would do such a thing. Oswald replied that he'd had to kill everyone living in the castle to save them from becoming chains trapped in the Abyss. Jack corrects him, saying that that wasn't what he'd meant, and that he wanted to know why Oswald made his Chains stop the chains from being destroyed. Oswald just smiled with the confirmation that it had been Jack who had severed them. Oswald and Jack fight each other, and Gilbert turns out. Jack wounds Gilbert and tells Oswald to withdraw or he'll kill his cute little servant. Oswald attempts to fight him anyways, but Jack severs his sword in half and when many of the Baskervilles attempt to aid their Glen, Jack uses Oz's power to slice them in pieces with chains.
Latowidge ArcEditGlen was the head of the Baskerville dukedom 100 years ago. According to Lottie, who had feelings for Glen, he seemed to like being alone and was unapproachable. Contrary to her beliefs, he was best friends with the loud Jack Vessalius and even told him about a secret passage so that he could sneak into the Baskerville house. Sometime after Glen suddenly ordered his subordinates to kill everyone in Sablier, it being the Capital at the time.
(This later turned out to be so none of the people in the area falling into the Abyss would be turned into chains.) All Baskervilles slaughtered everyone in sight, though they were reluctant, they had to follow orders. The incident later known as the "Tragedy of Sablier". Lottie relived her experience with Glen and Jack when she, Fang and Dug kidnapped Oz Vessalius in Latowidge Academy so she could draw out Jack and ask him where Glen's soul was.
When Oz, Alice and Gilbert traveled too far into the Inner Hole of Sablier, Jack, Alice and Gil were forced to experience their memories from 100 years ago, their memories of Glen Baskerville.  Tragedy struck Glen when Lacie was cast into the Abyss as a sacrifice. Glen was known to possess Pandora's Box, the legendary artifact that was said to contain all the world's misfortune before Pandora opened it. Glen himself opened Pandora's Box and was able to find Hope, which lead him to try and find a way to bring Lacie back, though to no avail as Glen soon lost his Hope when the world didn't offer him a solution. Glen then came to the conclusion that as the Box had lost its Hope, Despair was all that could remain, and therefore it was all that Glen could have. Lacie's sacrifice started to drive Glen to madness, which he used to fuel his obsession with taking control of the Abyss, through either the Intention of The Abyss or the harmony the Baskervilles had claimed that the Abyss was had. This is what caused Glen to lock Alice in a tower secluded from the rest of the Baskerville's estate, as she held a connection to The Abyss, thanks to Lacie. When Glen was in need of a new vessel, he found Gilbert was the perfect host. For the Transfer Ceremony to work, Glen must first transfer all of his Chains into the new body, Raven was to be first. Jack could not change Glen's mind, and lead Jack to discover that Glen wanted to obtain either the Harmony of the Abyss or the Intention of the Abyss so he could reclaim Lacie. Jack angered Glen in this way, and with his insistance, Glen threatened against his involvement. Glen was still going to follow through with the ceremony and because of this, Miranda Barma saw an opportunity. She taught Vincent Nightray how to open the Gates to the Abyss, which if done during the ceremony, would stop the transfer and save Vincent's brother. He did such and Gil was saved, but Glen was on the brink of insanity. When Oz reaches the Baskervilles door in the Inner Hole of Sablier, he finally came face to face with fragments of memories in the form of Glen Baskerville. Oz at first thought Glen was just acting as he should through the memory-sequence, as he continued to call Oz by Jack's name, but Oz is shocked when Glen knows him individually. Having lost Lacie, Glen appears to believe that the world is worthless and that not even hope or despair is left within him. Glen's negative aggression, added with the pressure of Abyss, caused Oz to summon Alice's power alone in a crazed state, which he is later pulled out of by Elliot and Leo.
Re Emergence of the Head Hunter ArcEdit
Glen was killed by Jack , who then went to both his and Glen's friend Arthur Barma, who agreed to perform a ceremony to stop Glen from ever returning and making such a Tragedy repeat itself. Arthur, and 4 other sorcerers (two being the ancestors of Master Rytas and Isla Yura) split Jack's body in five parts after his passing from a serious wound to the chest. They took both arms, both legs and his torso, and bound Glen's soul within them. They are to be guarded by the families of said sorcerers but already 2 have been shattered and one has been located.
The Feast ArcEdit
Glen Baskerville was not entirely human, more comparable to a Chain, as are the rest of the Baskervilles. Glen had to possess bodies in order to sustain life, and with each movement, Glen created Chains through his discarded bodies. He created Humpty Dumpty and it is assumed that is also how he obtained The Black Feathered Chains of Glen Baskerville, Jabberwock, Dodo, Owl, Raven and Gryphon. This transfer lets Glen keep his memories while the vessel's personality is retained. Humpty Dumpty was contracted to fellow Baskerville, Celia, for her close relationship to her superior as Humpty Dumpty's duty is to protect the Soul of Glen Baskerville. Glen knew that Humpty Dumpty would be first to find his soul if circumstances lead to it being misplaced. Glen explained all of this to Jack one day when he found Glen sleeping in a nearby forest. In a flashback, Jack and Glen was shown talking about how they are the same and different. Jack said that they were not much different from each other. Glen then told him that they were very much different from the normal people. He explained to Jack that Baskervilles don't die that easily nor on how they live. He will die like any other human, but there is much more to it. Before he is to die, he must choose a new "vessel" to hold his soul. Once the soul takes over the body, the consciousness of the vessel is gone. The memories and his soul will live in the new body. the body would become a chain as the body would be full of power from the Abyss. Jack wasn't sure if he wanted to see Glen as a chain. He heard that Jack had seen Celia's chain. He said that Humpty Dumpty was wonderful. He told Jack that Humpty Dumpty was the previous head of Baskerville's body. The chain has a special trait that other chains don't have. It has the power to search for the soul that it had before. It will protect the soul. Jack thought it was kind of romantic. Glen stood up and said that when Jack is around he had to speak about four times as much as he usually does. Jack thought he was joking around. Glen stare to the sky... if his soul was to wonder for 100 years without a vessel... surely it will be the first to find his soul. With a thread that it can only see... the thread that will lead it to his lost and wondering soul. As of Retrace LVIII, it is revealed that much like Oz, Leo has fragments of Glen's soul residing inside of him and they can communicate with Leo's subconcious. Glen constantly states that all the chaos with the Head Hunter is Leo's fault as Elliot stood by his side as his friend and died because of it; he must never forget that his ignorance caused this to happen.
Jack's Intention ArcEdit
After Vincent took Leo and explained the history of the Head Hunter and Barnard Nightray, Leo became a Baskerville, thus yielding to the fragments of Glen's soul which reside inside of him. Since then, Leo has become more crazed and delusional, much like Glen when Lacie was sacrificed to the Abyss, a lot of it coming from Elliot's death. Leo now feels that is his responsibility to carry out what Glen had started by obtaining and
destroying the Will of the Abyss to revert The Abyss back to the Paradise that it once was. Leo is now even willing to kill Oz for not cooperating with his plans, and he has also contracted with the last Glen's given Chain, Jabberwock Leo begins to talk about himself in the third person as his discussion with Oz progresses, it seems that Glen's soul is slowly starting to take over Leo's body as his own, no doubt caused by the breaking of three of the five Seals that prevent Glen from returning. When Oz tripped on the ground, Lacie's pocketwatch came out. It started to play it's tune. Leo stopped for a second to listen. Another flashback was shown: Before meeting Jack, there was another person who met him. Glen heard a voice calling him. It was Jack. He woke up to the voice. Jack was smiling, saying that he would catch a cold if he slept like that outside. Jack then asked if he was having a good dream. Glen said that of course he was not, and stood up. Jack looked up and saw snow falling down; he secretly thought that he hated the snow, even as he said he loved it, because it reminded him of the day he had met Lacie. In chapter 65, the last sealing stone revealed Glen's head instead of Jack's, thus confirming that it was Glen who used his body to seal make the seals instead of Jack using his body to seal Glen. Jack revealed his part in the lie as he used Oz's control over Alice to impale Leo with her chains, even as Oz cried out at Jack's sudden change, completely without warning. Gil remembered his previous house as Oz was "captured", and as he did the head broke from within the seal. He remembered Oswald/Glen writing at his desk, looking back over his shoulder at him from his place, with that uncharacteristic smile (up until this point) of love. He collapsed with grief, although all he remembered has not been revealed. Jack was shown after Oz had collapsed from his assertion, remembering his dark feelings of the world until lacie had come and found him. He then professed that he did not need friends, or status anymore as long as she was with him. It is currently unknown of how much truth rested within Jack's words, as this lie overturned everything the group had heard.
It is assumed that Oswald lost his fight to Jack, as Jack is seen alive later at Lacie's tower to see Alice. However, Vincent also at one point much earlier had told the Intention of the Abyss that Glen - Oswald at the time - had killed Jack.
Oswald possesses a somewhat recovered Leo and orders Gilbert to shoot Oz. Gilbert does so automatically and Oz falls to the ground while Alice screams in the back round. Gilbert looks on in shock at what he has done, and Oswald attempts to reassure him by saying that even after all this time, he was still his master.