Sanguine's codename has been with him ever since her joined Babel. He has not changed it, which could be seen as odd, considering how much of a negative connotation that name has in his mind. It's connected to all of the pain he has caused for others - he was not a good leader back then and much like the canon Doctor - used people under him as pawns more than people. It perfectly matches up with the definition of monsters that Vampire Sarkaz have been described as. Back then he sort of revelled in it and embraced it - picking out the codename Sanguine to reflect it - the color of blood.

But upon waking up from his coma.. He wasn't the same. Granted he still had some fragmented memories from back then but after seeing and hearing what has become of Babel because of him he sort of.. sobers up, and as cliche as it is wants to turn a new leaf. But he decides to keep the codename he used - finding a way for it to reflect his new self, taking more inspiration from the other definition of the word - to stay optimistic and positive, despite the bad situation.

He doesn't abandon it, because at it's core it is who he is - it still is reflective of his sins past, the sins he has to take responsibility for - but in turn allows that codename to become a symbol of who he wants to be first and foremost - someone who wants to give hope to others, no matter what the situation may be.

Ah yes my OC and I's amazing imagination and creativity /j

She was originally born as a Docsona then ended up as a proper OC. Her real name is still unknown for most due to this, and her codename is quite literally just the corvidae type she's based on, ravens.

She chose it because of its simplicity, as she didn't really need much more and after losing her family, her real name only brought her pain. It you make your research properly, you can still find out her surname is Wittelsbach and was a well known, swordsmen aristocratic family in Iberia's history.

Overly complicated codenames don't really go with her and much less with her way of thinking after she was forced to become a mercenary, so she stuck with Raven.

Jasper's true name is "Senchi" which come from the Japanese words "Senjutsu" and "Chīsai" which translates to Tactical and Small. Which she doesn't go by post her getting amnesia.

After waking up in Ursus, and wrapping her mind around the real reality that is happening around her, she only went by "Doctor" until she was able to find a fitting name she wanted to give herself. The gratitude she felt really impacted her, even with her voice gone, and the second chance she saw herself with lead her to the name "Jasper." Which means, "bringer of Treasure". With her "treasure" be one to help those in need on and off the Battlefield. Whether that be on the front lines, helping her team, or helping craft prosthetics for those in need on the Landship.

gonna do all of them :)

Raiden's is an english version of Raijin, the god of thunder and lightning in Japanese mythology. "Rai"vbeing Thunder and "Den" being Lightning. As for why they chose it, it's because it was their father's name since he was a higashi born Draco!

Hati is based on the Norse mythological wolf who's paired with Sköll. Being a Lupo it's kinda fitting why i picked it. As for why they picked it? knowing Hati they probably picked it off some old scripts.

Cascade is based on the Cascade Waterfalls which is unorthodox for a Liberi but it fits how her tail and hair feathers are blue + they like water. But it also represents how fluid and adaptable they can be. Cascade didn't choose her codename, more over it was given to them.

tl;dr im a nerd and like using references to myths

Sunless: Justino's name means "just", which is a pretty good descriptor for his moral compass. He took his codename during the Kazdel Civil War, when he was mired in tragedy and death which eventually compelled him to enlist as part of the front line forces despite never having been trained in combat until then. Justino had meant for it to be an affirmation that he would be by his fellow soldiers' sides, even if the sun were to disappear, yet in the end it amounted to a reflection of how dark his heart had become with guilt and despair. And on that note...

Sunrise: After certain events, he swore that he would never take his life for granted ever again after everyone had fought so hard to protect it despite the worst of his self-destructive tendencies flying right in the face of their efforts. The change to his old alias signifies the beginning of a long healing process.

Sourire: His real name is Oliver but is more commonly referred to as "Oli." I picked this as his name because I'm cringe and wanted to make a very light reference to a band I listen to by the name of Bring Me The Horizon (the lead singer of the band being Oliver Sykes). His codename means "to smile", which is both a sort of jab at himself and a reminder of what he should continue to bring to others. Even if his life has ultimately changed directories thanks to the horrible Oripathy infection forcibly inflicted upon him, all he wants is to help make a better world with the time he still has.

Aberration: His real name is Nox, a gender-neutral name for "night". As for his codename, he first took this mantle up because he felt like the odd one out at Rhodes Island but eventually his view on the codename began to change. It soon became an expression of his own individuality, something that the sea and its myriad monsters could never take away from him.

I have reasons for all of them, but I'll start with "Astoria" - originally, I went into Arknights completely blind and put in my usual nickname of "Tori". I wanted to make it sound a bit more 'professional' after getting full context, and my usual name choice of Victoria was spoken for. So I spat out the name Astoria instead, which turned out to be an Old English name meaning 'hawk'. So it stuck for the hilarious irony. Her surname of "Frostulf" is similar; it's "Ice Wolf" in Nordic, and felt even funnier to attach to a character based off of a rabbit.

Astoria's actual birthname of Shanti is a Hindi word meaning "Tranquility", and is a stealth pun on her being a moon rabbit; she's technically named for the Mare Tranquilitas-

Crux's real name is Amene! From what I had found, Amene can mean "Looking forward with hope", something he tries his best to do after waking up from his coma and eventually when he regains his memories. Crux as a codename on the other hand, can mean a decisive point, but is also something that was used physically as a means of torture, which during his pre amnesia days Crux was known for his brutal interrogations that typically involved psychological torture.

For Valerian, since he's a doctor and works with blood, people and especially kids might be a little bit scared when they have to see him, on account of all the needles and stuff that comes with blood work. In real life,
the valerian is a type of flower that is more recently promoted in things like anxiety relief! His real name Sol, aside from coming from when I was on a Guilty Gear lore binge, was because for Crux and Blaze, when he was born it was like they were staring at the sun, knowing their little boy had a bright future ahead of him.