We are introduced to Ange at Naos Base. The party first encounters her when they're attacked by a large machine, known as a Gigantess, and they realize that it's actually being powered by a girl -- Ange. She's being held inside of a tube in the back of it, while in an almost sleep-like state. After taking out the machine, the party manages to get Ange out of it before it can explode, thus saving her life.
The party, incidentally, is not aware she's actually the Avatar they've been looking for. After finding out who she is, they talk a little about Avatars and what Ange did to get herself captured. It turns out that, not long before the party reached Naos, where they heard Ange was supposed to be, she destroyed the city's cathedral. The memory circle in the cathedral caused her to awaken to the fact that she's an Avatar, and it resulted in her destroying the cathedral with her newly awakened power. She's been extremely depressed because of that, and the party tries to reassure her and make her feel better. During this conversation, Ange finds out that Luca's past life was none other than Asura.
As it turns out, Ange's past life is Orifiel, Ratio's most resourceful warrior. They then have a flashback where Asura gives Orifiel the choice to either die or surrender. Asura and Orifiel happen to be on different sides of a war -- a war that happened many years ago in a land called Devaloka, which is basically heaven (and it eventually collapses at the end of the war, meaning it no longer exists, leaving only the world they're on now -- Naraka). Asura is of the Sensus, while Orifiel is of the Ratio. Orifiel tells Asura that he has no intention of dying, and Asura proceeds to praise Orifiel. Orifiel then says that their strategic objective was fulfilled, so there is no need to battle anymore -- his objective was to allow the citizens of a nearby village to escape unharmed. After more conversation between the two, Asura says he's come to like Orifiel, and allows him to run away.
After the flashback, an alarm sounds, and the party rushes to exit the base. On their way out, they meet a man named Ricardo, who is in search of Ange. Ricardo must bring Ange back to a man in Tenos, because he's made a contract with this man. Ange refuses, and decides to make a contract with Ricardo instead. She gives him an extremely valuable necklace, and is able to pay for both the breach of contract (he isn't bringing Ange to the man in Tenos anymore, so he must compensate the man whom he made the contract with), and is also able to pay for the new contract that she makes with him -- which is for him to be her bodyguard. After this, the party tries to leave again, when a man named Gardel arrives. They take him out, and finally leave the base, and heads for Naos.
Upon arriving at Naos, they realize that Ange's famous in that city, so they decide to hide out at Hartman's house. This is where Ricardo tells Ange that the man in Tenos's name is Albert, but Ange doesn't know him. They end up assuming he's searching for the Manifest, or gathering Avatars, or other things of that nature. After more conversation, they head to Regnum, where they meet Hermana while hiding out in sewers. They decide to help her find a special mushroom that's deep within Regnum Cavern, so they head in there. There happens to be a memory circle in here, which is something that is able to show them memories of their past lives. The memory it shows is of all of their past lives after the war in Devaloka has ended. Orifiel mentions to Asura that Himmel has died, and he thinks it may be because they sought to punish him for his (Orifiel's) betrayal -- he's gotten quite close to Asura. Afterwards, they retrieve the special mushroom, and head out.
On their way out, they meet a boy, Chien, whom is looking for the Manifest and has brought two dogs along with him -- this is when it's made quite obvious that Ange is afraid of dogs. After defeating the boy in battle, they exit the caverns, and Hermana decides to tag along on their journey. They then head back to Naos, check out the library there, and find a few places they can go to find more memory circles -- after which they board a boat and head to Ashihara.
At Ashihara, the party gains entrance to the town's tombs, and finds various murals about Devaloka and the Primeval Giant, as well as a memory circle, which contains a memory of Inanna and Asura speaking. Afterwards, they leave, fight a girl named Chitose on the way out, and board a boat to Garam.
At Garam, the party tries to enter the Kelm Volcano. They're stopped before they enter, and told that Hasta is in there -- a crazy, bloodthirsty man, who is also an Avatar. The party tells the man they'll take out Hasta, and he lets them enter. It's in Kelm Volcano that Ange starts to act really weird, and it's due to the heat. As it turns out, she absolutely does not do well in heat. Not much further in, Hermana brings up Ange going on a diet, which sets her off -- she's sensitive about her weight. Ange scolds Hermana quite a lot, and has to be told to stop before they can press on. Putting that aside, the party continues to treck through the volcano, and ends up meeting Hasta when they reach the memory circle. The flashback that comes from the memory circle is one that involves Gaebolg (Hasta's past life), Durandal (Spada's past life), and Asura, and they're about to engage in a fight. After the flashback, the party fights Hasta, and Luca ends up getting stabbed, so they take him to an inn in Garam.
After he wakes up, the party boards a ship to Galpos. There, they find out Chien's around, and head into the Galpos Jungle. While making their way through the jungle, they meet an odd man named Grandpa Pwo, who sings odd songs, but they find out from him that what they seek is in the heart of the jungle, so they continue further in. He was right, too, because they do in fact find the next memory circle there, and they get a flashback of Orifiel and Asura talking about how to use the Manifest. However, after the flashback, Chien arrives, and the party tries to get him to join, though it's to no avail -- he fights them, and then runs off. So, they leave the jungle, having gotten what they came for, and board a boat back to Regnum.
There, they have to wait for another boat, so they decide to hang around the city for a while. When they get back to the harbor, Ricardo turns on them, revealing that he is now working with his past life's brother, Gardel (past life name being Thanatos). The party is really surprised that Ricardo would actually turn on them like this, and Ange states that she always believed he was someone who would honor their contract -- he's breaking it by turning on his own client. Mathias then shows up and says the party will be sent to the Grigori Village (an unescapable village on an island out in the sea), where they will be confined.
Upon arrival, the party decides to check out the village; it's quite small, bare, and boring -- they don't want to spend the rest of their lives there. While the party explores, Ricardo and Gardel have a talk, and Gardel tells him that he plans to perform surgery on them in order to extract their memories, possibly at the cost of their minds. After this, they're invited in a house to eat, and they all have a conversation about what they want to do with theirselves in the future. Ange wants to retire to a small church out in the countryside, possibly in a town with delicious food; a quaint village in the wine country, perhaps. Although, everyone begins to feel sleepy, and one by one, they all fall asleep.
Ricardo ends up saving them before they can be harmed, and they all wake up on a boat. He apologizes, and Ange says she placed great faith in him when she gave him that valuable necklace. Ange soon reveals, in a conversation with Luca, that she was pretending to believe in Ricardo that whole time (between his betrayal and now), proving that she can be quite convincing, as well as underhanded. After the party speaks a bit, Gardel attacks them, but loses. Then, following the battle with him, a Gigantess, being operated by one of the Grigori, attacks and blows Gardel away when he tries to stop it -- the Gigantess is also defeated by the party.
Their time spent in Mamut is short, only passing through to get to the battlefield to the north. Although, before they can reach it, they have to pass through Lemures Marsh. Upon entering the marsh, Ange has an odd feeling about the place, and they soon realize that there are a lot of dead soldiers walking about. They fight their way through the marsh, and when they reach the end, a monster appears. Ange seems to recognize it, but they engage in a battle with it before she can say anything about it. However, after the battle, the monster recognizes her as Orifiel, and begins repeating that name. It doesn't even know it's on Naraka; it still believes it's on Devaloka. This monster actually turns out to be souls that lingered instead of passing on, but Ange tells them they have earned peace, and may now do so.
A flashback is then initiated. In it, Himmel is confined, and sentenced to death for being corrupted -- which is blamed on his tutor, Orifiel, for being too lax. Orifiel then confronts Himmel and apologizes, but also says he is considering proposing an alliance to Asura. Himmel does not approve of this, telling Orifiel he'll be branded as a traitor, but Orifiel doesn't care about that; all he cares about is saving Himmel. He swears to return with Asura to save Himmel, and then leaves -- after which, Himmel says he will wait for Orifiel because he knows Orifiel would never betray him.
After the flashback, the party makes their way out of the marsh, and onto the Northern Battlefield, where they once again meet up and fight with Hasta, who ends up getting away. The Northern Battlefield doesn't take much time to get through, and upon exiting, Ricardo reminds Ange of Albert -- they're now in the north, where Tenos is.
There's more talk about Ange's ability to eat at Tenos, and she gets rather upset about it, later telling the other girls that everyone hurt her. Although, after going further into the city, they overhear two men talking about Albert and where he was headed -- which is a point of interest to the party, and they decide to try and go to where Albert is going. They don't want to be caught by him, though, so they plan to get there before him, investigate, and then leave before he arrives.
So the place they arrive at is the Celestial Garden, and the party immediately notes how cold and lonely it feels. Here, Ange mentions that she is sensitive to the cold -- apparently both hot and cold extremes can get to her, although she is much worse off in the heat. About halfway through, Luca and Ricardo talk about Albert and what his possibly motives could be, while Ange has a flashback -- a flashback of Orifiel meeting with Himmel, actually. Himmel states that the Ratio elders still don't seem to realize how essential it is to reunite Devaloka and Naraka, and Orifiel tells him to be patient and that he will save him -- to which Himmel replies that he will wait. They then have a conversation about what's currently happening within the Ratio and the rest of Devaloka. At the end of it, Himmel tells Orifiel that he's waiting for him, and that he only has him to depend on. He'll wait for him forever.
Ange begins acting weird after that, likely thinking about how Orifiel never went back to save Himmel -- he failed him. Soon after the flashback, though, they reach the memory circle. Hermana rushes into it, and activates the flashback -- where the Overlord is shown speaking to the public about the Manifest, and promoting the unification of Devaloka and Naraka.
Afterwards, Hermana tells the party she knows where the Sky Castle is and they decide to head there next, but first a young man shows up with a couple soldiers. He introduces himself as Albert, proving that he is the man who asked Ricardo to retrieve Ange for him. He soon asks if Ricardo has brought her, and Ricardo tells him he didn't bring her here for Albert's sake.
Ange asks him why he wanted Ricardo to bring her to him, since she has never even met Albert before.
"Don't say things like that, Orifiel..."
It's at that moment that Ange realizes it -- she realizes that Albert's past life is none other than Himmel.
This is the canon point I am taking her from.