Carl was born to Relius and Ignis Clover in the 2nd Hierarchical City of Iwatsuchi. He grew up in their family household, becoming fond of playing chess and the violin, but most of all, playing with his older sister Ada. At some point, he was enrolled into the Novus Orbis Librarium's Military Academy.
In the short span when Carl attended the Military Academy but had yet to realise that Ada had been turned into a Nox Nyctores, he was invited over by Makoto Nanaya to have lunch with her group (Team Remix Heart) on one day. He was introduced to Mai Natsume, who he took an immediate shining to as she reminded him strongly of Ada herself. He struggled to keep track of the conversation regarding Mai's feelings towards Taro Sasaga'e, and wasn't seen in the manga for the rest of the series afterwards, presumably because he dropped out at some point to take care of Ada.
Escaping from the family household with Ada in tow, Carl arrived at his uncle and aunt's house 3 days later in the dead of night. Having woke up his uncle and aunt, Francis and Rosenne, they took him and Ada in. After Rosenne called Ada a 'doll', Carl had an explosive outburst, claiming that she was unchanged, and still family; he then began to explain what Relius had done to her and was driven to heart-felt tears. Rosenne stared at her niece, unable to imagine how someone so beautiful and bright had been turned into an expressionless doll, she then asked that the two do not stay in the same room when he slept as she was wary of his safety, with this, Carl's eyes pleaded with Francis to say otherwise. Eventually, Francis complied and allowed the two to stay together regardless. When the two went to bed, Ada tilted her head in an attempt to make a gesture; Carl eventually fell asleep studying the gesture.
|Stage IV: Bang Shishigami|
Bang: What's the matter, young man? You seem to be in trouble. Oops! Excuse me, my name is Bang Shishigami. I make my living as a vigilante. No need to be alarmed though. I am a vigilante, but I'm a vigilante of justice.
Carl: I seem to have lost my way. Thanks for helping me out. My name is Carl Clover. I may not look like it, but I too am a vigilante. I guess that makes you my role molde.
Bang: No kidding! That must be tough for a man your age.
Carl: Oh no, it's not that bad. I have to admit, I've never seen a ninja until now! If you don't mind, I'd love to see one of your techniques for future reference.
Bang: Oh, ho! Such a well-mannered young man! All right, as a role model--or better yet, a big brother--I'll allow you to practice your moves on me!
Carl: That was very helpful. THank you so much, Mr. Bang.
Bang: Haah...haah... O-Oh yeah...if you need anything at all...haah... don't hesitate to ask me, all right? Haah...haah...
Carl: Didn't you have a good time, Sis? It was fun, wasn't it? ...Heheh.
|Stage VIII: Litchi Faye-Ling|
Litchi: Ah! Excuse me, please wait!
Carl: Ah, yes?
Litchi: Is that Nirvana? Why is it here...? Where did you get it?
Carl: Everyone calls my sister that. Do you know her?
Litchi: Eh, uh... I'm sorry, but I really can't tell you... All I can say is that if you keep this up, something bad is going to happen.
Carl: Why do grown-ups always hide things? Hey, Sis, this lady knows something, doesn't she? But, she won't tell me... Sad? Yeah, you're right. This is unacceptable.
Litchi: Poor boy... Deus Machina Nox Nycores Nirvana... the machine that causes madness... It would appear that what the professor said was right...
Litchi: Guh, argh, guah, s...stop...
Carl: Oh, please don't lose consciousness yet. ...I knew it. Counting on grown-ups is never a good idea. Can we go now, Sis?
|Stage IX: Hakumen|
Hakumen: Hm, is it you, Deus Machina? It's been a long time...
Carl: I'm sorry, but do I know you?
Hakumen: Just think of me as her comrade. You've been defiled though, haven't you, Nirvana? Your hands were never meant for hurting people.
Carl: Don't call my sister Nirvana.
Hakumen: What a pathetic puppeteer. Let me give you a piece of advice. The driving force behind Deus Machina is a person's killing intent. Their desire to kill. Deus Machina drives people insane? Ridiculous. Your desire to kill simply directs the Deus Machina. Trying to shift the blame is pretty pathetic.
Carl: Shut up! What do you know!? You don't know anything about my sister! You don't know me either!
Hakumen: I certainly do not understand you, but I have no need of understanding. What a pathetic human body. You lost all hope and turned to evil. That makes you my enemy! I am the white void. I am the cold steel. I am the just sword. With blade in hand shall I reap the sins of this world, and cleanse it in the fires of destruction. I am Hakumen. The end has come!
Hakumen: Gah, how dare you interrupt me, Grimalkin!
Carl: Huh? ...He's disappeared. He was really strong. I'm glad you're safe, Sis. ...I'm a bit...tired.'
|Stage X: Nu-13|
Sheol Gate AD2199/12/31
Carl: Evil, huh? ...You know what, Sis? I will do anything for you sake.
Nu-13: Loading...loading...loading...loading... Complete...
Carl: Father may have turned you into this, but I'll find him. I'll find the Azure Grimoire, and I swear I'll take it.
Nu-13: Target recognized. Auto-mode: activated.
Carl: If that's what mankind considers evil, I will gladly bear that name.
Nu-13: Target identified: obstacle. Elimination protocol release requested... Request granted.
'Carl: All right then... Let's go, Sis!
'Nu-13: Activate elimination protocol.
Carl: What is this light? It's white and warm... It's just like my sister...
Look, Sis... This guy is called Ragna the Bloodedge. Is this information any good though? I wonder why the drawings on wanted posters are always so terrible. Don't you, Sis? Heheheh... Anyway, if this information is valid, Ragna the Bloodedge is supposed to be in Kagutsuchi right now...
Hm? I know, Sis. Don't worry, I won't overdo it. I promised. All right then, let's go collect some more information. It looks like some people from the Guard are coming. Any information from the Librarium should be reliable. Maybe we'll run into the "Hero of Ikaruga" too, if we're lucky.
Don't worry, Sis. I'll help you. Let's find the Azure grimoire. I think it'll be the solution to our problems.
A Vigilante belonging to the highest class. Although young, he has excels in both talent and skill. Alongside a mysterious doll named Nirvana, he eliminates criminals. After receiving information about the great criminal "Ragna the Bloodedge," he heads for Kagustuchi.
Now an established vigilante, and hearing about Ragna the Bloodedge being the possessor of the Azure Grimoire, Carl travelled to the 13th Hierarchical City of Kagutsuchi in the hopes that the grimoire could somehow help return Ada back to her original state. Around midnight on the 30th of December, 2199, Carl was near the Kagutsuchi NOL branch with Nirvana before being greeted by Hakumen. The boy correctly deduced that he was the genuine member of the Six Heroes given his appearance and that he was wielding the Interfectum Malus: Ookami. Hakumen told Carl to abandon Nirvana and that its mental affects will be too much for him to burden. Angered that the hero was impeding his progress, Carl began to threaten him but was shocked when his sister stood between them both as Hakumen began to draw his sword. Before the fight could ensue, Nirvana grabbed Carl and leaped to a nearby rooftop to protect him, ever so aware of Hakumen's incredible power thanks to the time they spent together in the Dark War. 
Carl is only briefly seen when he was resting in the fields of Kagutsuchi, with Nirvana carefully watching him and keeping guard.
A boy who works as a bounty-hunting Vigilante. He pursues the "Azure Grimoire" in order to regain his true sister "Ada." He tracks its owner, Ragna the Bloodgedge while accompanied by the self-moving automaton and Causality Weapon "Nirvana."
Transcript of Carl's Continuum Shift arcade.
|Stage IV: Tsubaki|
Tsubaki: A-Are you... Carl? What have you been doing until now? You disappeared suddenly and we were all worried about you...
Carl: Long time no see, Tsubaki. That uniform... You're a member of Squad Zero. What are the Librarium's trash collectors doing in Kagutsuchi? Does it involve Ragna the Bloodedge?
Tsubaki: ... Why would you ask that?
Carl: Well, you see, I'm currently a vigilante... And I happen to be looking for Ragna the Bloodedge. Do you think you could tell me what you know?
Tsubaki: ... You must know I have no obligation to do anything of the sort.
Carl: Is that so...? I actually kind of like you, Tsubaki... What a shame. Well if you won't tell me, then I suppose I'll just have to get my information the hard way.
Tsubaki: Carl!? What are you-
Tsubaki: Carl... Y-You... Ugh...!
Carl: And there she goes... No, it's OK, Sis. Let's keep going.
|Stage VIII: Litchi Faye-Ling|
Carl: ... You again... Ugh!
<Both Litchi and Carl wince in pain>
Carl: Wh-What was...?
Litchi: Was that... information flowing in from the Boundary? Then...! C-Carl!?
Litchi: you and Nir- your sister need to get out of Kagutsuchi. You need to stop chasing after Ragna!
Carl: How do you know we're...?! Just who are you? How do you know about my sister? Do you know her!?
Carl: Figures... You're not going to tell me, either... Adults are so selfish... They never see my sister for who she is... You probably think you're doing this for my own good or something, but it's not good for me at all, so why don't you just stop it!
Litchi: Th-That's not true! Why would I-
Carl: Oh please, drop the "nice adult" act. I've fallen for lies like that too many times before.
Litchi: Please, listen to what I have to say...
Carl: All I want... All I want is to stay with my sister!
Carl: Sis...? Why? Move...!
Litchi: ... Stopped...? You...
Carl: No! I'm... I have...! Please, stop! Leave me alone!
Litchi: Ah! Hey! Wait!
|Stage IX: Rachel Alucard|
Carl: Sis, are OK? You must be a little tired. Sorry I didn't notice earlier... Sis? What's the matter? There's no one here. !? You... Where did you come!?
Nago: Oh my. Still can't let go of your sister? That's kind of creepy, you know...
Gii: A sister-complex!
Carl: Uwah! A-An umbrella and... a bat... are talking!? ... Are you... a witch?
Rachel: ... You never change, do you? Well, perhaps you have grown... a little. Hehe. Even so, I fear you shall never return her to her original state, no matter what you may think...
Carl: !? ... What do you know?
Rachel: I know very little of your sister, but I know a great deal about that thing you seem so attached to. Nox Nyctores Nirvana... one of the great weapons that survived the Dark War. It feeds on one's thirst for blood, and will not stop until all its foes have been eliminated. Still... your doll seems a rather friendly one.
Carl: The Dark War...? Stop making up nonsense! My sister is not Nirvana! She's always been there for me! She's not a doll...!
Rachel: ... You are as much a spoiled brat as ever, aren't you? Merely looking at you makes me feel... ill.
Carl: "Nirvana" has nothing to do with this. This... is my sister.
Rachel: Hmm? Perhaps you have matured, however little. ... Noel Vermillion lies ahead. Find her, and you may find that which you seek.
Carl: Noel is... Why...?
Rachel: You now have a reason to proceed... Which future will you choose?
<Rachel teleports away>
Carl: She disappeared...? Yeah there's no point in thinking about it. Let's go, Sis.
|Stage X: Hazama|
Hazama: Oh my goodness... How did a child get in here? What does security think they're doing?
Carl: Um... I heard Miss Noel Vermillion was here, so I...
<Nirvana attacks Hazama>
Hazama: Oh-ho! Always nice to see a familiar face. I didn't know you were still up and about, Nirvana.
Carl: ... You know my sister? ... Who are you?
Hazama: ... Sister? That thing isn't exactly an action figure, kid.
<Nirvana attacks again>
Terumi: Damn... this is a pain. Noel Vermillion, huh? That damn vampire sent you, didn't she? Right? Well, you're too late. Noel's taking a little nap just now.
Carl: Don't tell me... She's inside that sphere...?
Terumi: Who knows? You did kind of invite yourself in, but I'd be a terrible host if I didn't show you some sort of hospitality... How about I entertain you for a while!?
Carl: Ugh...! Sis, let's retreat!
Terumi: Restriction 666 released! Dimensional interference force field deployed! Heeheehehehe! Lemme show you what -real- power looks like, kid! Code S O L. Azure Grimoire activate!
Carl: BlazBlue!? Why... Why do you have the Azure Grimoire!? That's Ragna the Bloodedge's-
Terumi: That chump? Hey, kid, you got it all wrong. Didn't you know? I created the Azure Grimoire!
Carl: Uh... Uhhh...
Terumi: Well, that was fun. Nice warm up... Need to learn to push myself, though.
Carl: Sis... what? Huh? Beast... Black... Beast...?
Terumi: The Black Beast? What the hell would I want with that failed experiment?
Terumi: Yeah, a huge failure. Real pain in the ass to keep the Cauldron under control. But hey, we learned all sorts of shit in the process, so, you know...
Carl: ... Cauldron?
Terumi: Wait. You came all the way here, and you don't even know that? Damn. Hope you didn't think the Grimoire was, like, a weapon or something... Yeah, the Cauldron. What, did I mumble? The Cauldron's the Grimoire's original form. It gathers souls to smelt the sword inside its body. That was our little pet - the Beast.
Terumi: You've got Nirvana, you met the 13th subject, right? Didn't she tell you? The Murakumo Unit's incomplete. It need's Ragna - his Grimoire really - to be whole. But this one... this one's different. This thing embodies the TRUE Azure!
Terumi: Now... Murakumo...activate! This world is nothing but lies! LIES!
Terumi: Lemme show you what I like to call the truth! The truth called "despair"! In the name of Susanno'o, I command you! Murakumo, AWAKEN!
Terumi: Behold the sword of the god-slayer, KUSANAGI!
Terumi: Let all that lies fall before your divine blade!
Terumi: Gaahahahaha! Finally, I've got the true successor to the Azure! Try and stop me NOW, Master Unit
Stumbling around Kagutsuchi eventually lead Carl to Ragna by pure chance. Determined to take the Azure Grimoire for himself, Carl attacked but had a crippling loss, but Nirvana managed to deal a deep blow to Ragna. Carl was found by Bang Shishigami and was taken to Litchi Faye-Ling's clinic, but since Litchi was nowhere to be seen, Linhua saw to Carl's treatment. Noel served as Carl's target when he awoke as Nirvana's emotion amplification had twisted his mind into believing her as a genuine threat, when all she was attempting to do was help the young boy. Bang interrupted the unfair duel which sent Carl scampering away.
Once in the Hanging Gardens far away from Orient Town, Carl consumed a healing Ars Magus potion that he bought from a street shop vender. Soon afterwards, he came across Tsubaki Yayoi, and demanded that she tell her more about her his father, Relius Clover. Tsubaki refused, which lead to Carl violently attacking her, and eventually, even beating her. Before dealing a further blow, Makoto intervened, saving Tsubaki from Nirvana's crushing claws; seeing a perfect opportunity, Carl asked if Makoto, a member of the Intelligence Department, would help him in his search for Relius. Instead of handing over the information, Makoto picked up Tsubaki and fled.
Nirvana sensed Litchi in the NOL branch, and lead Carl to her. The doctor expressed immediate concern for the young man since the effects of the drug he took has a crippling after-effect on its users, and was developed for soldiers on the frontlines of the Ikaruga Civil War. He began an assault on Litchi but the drug forced him to stop, and not long afterwards, he began to weep in Litchi's arms as the reality of his life and Ada's condition finally hit him.
Relius enters the scene, forcing Carl to immediately strike him out of pure hatred – his father completely ignored him, instead marvelling at Nirvana and Ada's “cooperation” with the experiment to turn her into the doll. Carl and Nirvana reared back and began to attack, however, this was blocked by the Fluctus Redactum: Ignis. Before Relius could truly attack, Nirvana transported both Litchi and Carl out the area. Tears streamed down Carl's face as he screamed, having realised that the Ignis is his own mother, Ignis Clover.
A boy who works as a bounty-hunting Vigilante, accompanied by the self-moving automaton and Causality Weapon "Nirvana." He travels to Ikaruga in order to search for the owner of the Azure Grimoire, Ragna the Bloodedge, and Kokonoe, who knows about Casuality Weapons. That place — where Ignis was created.
In Ikaruga, Carl discovered that both Ragna and Kokonoe were nearby, leading him to pursue them respectively for the Azure Grimoire and answers to his sister's condition. Soon enough, he arrived in the 8th Hierarchical City of Wadatsumi, where he met Bang and Platinum the Trinity. Platinum made an inappropriate comment about Ada's condition, leading Carl's anger to explode in an attack towards Luna, and he rejected Bang's offer to show him the city. He left them both, explaining he was destined for the 6th Hierarchical City of Yabiko. On the way there, in the 7th Hierarchical City of Kazamotsu, Celica A. Mercury happened upon him and repeatedly called out to Nirvana. Irritated, he attempted to battle her but was interrupted by Hakumen; he lost to the hero and continued onward to search for Relius.
Following Nirvana's guidance, Carl found himself face-to-face with Relius and Ignis. They talked about Litchi and her decision to join the NOL, and finding himself so enraged with Relius' personality, Carl attacked as soon as possible, but was unable to even scratch the man. Relius left after promising that he would rebuild Ada, should the time come. After leaving the area, Amane Nishiki brashly approached him and begged him to join his traveling troupe. Carl gave him little chance and left as soon as the opportunity arose, in no joking mood after his meeting with his father.
Near Kushinada's Lynchpin, Carl deflected a blow from Ragna that had been directed towards Relius. Litchi and Bang begged him to not join the fray, but he ignored them in pursuit of Ada's cure. Nirvana and Ignis' tag-team prevented the opposition from advancing, but the two were soon split up with Carl taking up arms against Izayoi. After losing, Carl protected Relius and evacuated them, insistent on him fulfilling his promise to save Ada from her mechanical condition. Litchi aided him in taking his father out of the area.
A young Vigilante, who nonetheless excels in both talent and skill. Controlling a mysterious doll named Nirvana, he eliminates criminals. In order to cure his sister's illness, he sets his eyes on the "Grim Reaper" who possesses the "Azure Grimoire."
Both Carl and Nirvana were taken inside the Embryo, and the former had his memories altered so that he didn't believe that Ada was inside Nirvana, and that she was instead bedridden at the Clover family home.  In an alternate Roningai, Carl found Ragna and Tao, whose memories had also been changed. He knocked Tao flying with Nirvana, and demanded the Azure Grimoire. He lost the fight against the Grim Reaper, being forced to retreat, but not before causing a serious wound with Nirvana. 
The following day, Carl began wandering around Kagutsuchi and met Nine the Phantom who mocked him for being ordinary compared to his father. She told him that Relius was partially responsible for bringing the Dark War open the world, feeling he had a right to know as their fathers had both worked together.  He was later transported to Ikaruga and by Nine and told to kill Izanami in order to secure his piece of the Azure 
In the 6th Hierarchical City of Yabiko, Carl was found by Celica, whose memories were unaffected. She told him about Ada being inside Nirvana, a truth he did not want to accept, even after Nirvana refused his order to assault her former mistress. Memories began to flood back to him, and he ran away from the mage. 
It would not be long until Carl's memories had truly returned. He apologised to his sister for having forgotten about her and pondered on what actions he could take, eventually settling on pursuing Relius in the search for more knowledge in the hopes that he could cure Ada without killing Noel.  Carl found papers dating from 2098 with Shuichiro Ayatsuki and Relius' names printed on them. He came to the realisation that his father had travelled through time using the Boundary. He found Jin and Trinity Glassfille preparing to modify Platinum the Trinity's body so they could exist within the Embryo, and he offered his assistance to gather experience.  In time, he found his father, and asked to be taught all of his knowledge, to which he complied. He learnt of the Prime Field War, believing that the humans who started it were selfish.  Confronted with this new knowledge, Carl initially rejected it before realising that Relius had seen this with his own eyes. 
Carl looked into the Kagutsuchi cauldron, forcing Ada to let go of his hand in order to do so. He was nearly swallowed into the Boundary until his sister saved him. By peering into the Boundary, he had been given an eye similar to Relius, and he had seen the form of the world.  Soon, Carl evaporated into seithr, and was reborn in the new world created by Ragna. There, he was seen with a mask over his changed eye, and he wandered around the world with his sister. 
- BlazBlue: Calamity Trigger Official Site (JP), Carl Clover
- BlazBlue: Calamity Trigger - Part 2, Chapter 3 - False Hero
- BlazBlue: Continuum Shift Extend Official Site (JP), Carl Clover
- BlazBlue: Chrono Phantasma Official Site (JP), Carl Clover
- BlazBlue: Chrono Phantasma, Story Mode, Chrono Phantasma, Episode 1: Unexpected Encounters
- BlazBlue: Chrono Phantasma, Story Mode, Six Heroes, Episode 7: Destined Rendezvous
- BlazBlue: Chrono Phantasma, Story Mode, Chrono Phantasma, Episode 8: Reunion
- BlazBlue: Chrono Phantasma, Story Mode, Episode 17: Doomsday
- BlazBlue: Chrono Phantasma, Story Mode, Episode 18: Beginning of the End
- BlazBlue: Chrono Phantasma, Story Mode, Six Heroes, Episode 7: Destined Rendezvous
- BlazBlue: Central Fiction Consumer Edition Official Site (JP), Story - Carl Clover
- BlazBlue: Central Fiction, Arcade Mode, Carl Clover, Act I
- BlazBlue: Central Fiction, Story Mode, Episode 002, Chapter 008
- BlazBlue: Central Fiction, Story Mode, Episode 003, Chapter 021, Sub Scenario 1
- BlazBlue: Central Fiction, Story Mode, Episode 005, Chapter 036
- BlazBlue: Central Fiction, Story Mode, Episode 007, Chapter 054
- BlazBlue: Central Fiction, Story Mode, Episode 008, Chapter 062, Sub Scenario 1
- BlazBlue: Central Fiction, Story Mode, Episode 009, Chapter 069, Sub Scenario 1
- BlazBlue: Central Fiction, Story Mode, Episode 009, Chapter 073, Sub Scenario 2
- BlazBlue: Central Fiction, Story Mode, Episode 010, Chapter 081
- BlazBlue: Central Fiction, Story Mode, Episode 010, Chapter 081, Sub Scenario 1
- BlazBlue: Central Fiction, Story Mode, Episode 011, Chapter 091, Sub Scenario 1
- BlazBlue: Central Fiction, Story Mode, Episode 012, Chapter 100