When all of this starts, Reginald doesn't have a complicated system to the name the children he acquires; he simply names according to the order in which he finds them. Thus, when he gains custody of a small, pale child with wisps of dark, curling hair, he calls him Number 3.
They are three years old when their powers really begin to emerge. That's when Reginald decides a renaming is required. He sits down with each of the children and performs tests in order to determine their potential. Number 3 shifts up to Number 2. After all, a link with the dead has the potential to be quite remarkable indeed.
When they turn five, mom decides that her children need more than numbers as names – to promote wellbeing and healthy adjustment, she reasons, and Reginald indulges her enough to leave the naming up to her. She takes the duty very seriously and Number 2 is worrying his lip when mom bends down to him, smiles warmly, and says, "And you, my dear, are Arthur."
He immediately shortens it to 'Artie'.
For the next few years, Artie is content being both 'Artie' and 'Number 2'. Things change once more when Reginald announces they are going to have a tournament to see which of the children is now the strongest. Vanya is automatically excluded, so she'll be remaining Number 7, but for the others, they have the potential to move up in the ranks.
Ben forfeits every match he takes part in. This isn't through cowardice or any fear of harming his siblings (which he could very, very, easily do) but because he simply finds it a waste of time. He doesn't care about his number, certainly not enough to attack his siblings over it. Reginald instantly makes him Number 6, hoping the 'insult' would snap him out of his apathy, but not for the first time, Reginald is bitterly disappointed.
Five also doesn't take the tournament seriously. Maybe it's because he wants to keep his name, which he prefers over the one mom gave him, or maybe it's because he enjoys annoying Reginald. Most likely, it's both. Five teases his opponents, dodging attacks with his jumps and laughing as he jumps too high for them to reach. This lasts until he either runs out of juice or Reginald grows frustrated enough that he stops the match early. Five never sees the end of the tourney, having been sent to his room after jumping right behind Reginald, startling the man more than he would ever admit.
Ben and Five's reluctance to play Reginald's game is the only reason Artie gets Number 4. He's still not over his fear of the dead, despite Reginald's best efforts, but at least he tries. He uses the hand-to-hand combat training they've been given to at least keep up with his siblings until they bust out their power. It's with a heavy sigh that Reginald 'awards' Artie Number 4 and he feels anything but proud.
Aged 11, Artie begins to experiment. He's always liked the dresses Allison gets to wear on their days off, and always wanted to try the make-up he's seen in pictures when they've gone out on missions. He decides it's finally time to try it out for himself. He goes to Allison, asking if he can try on her clothes, and though she's initially confused, they end up having a lot of fun with it. Allison was never allowed many dolls growing up so this is heaven for her. It's after playing dress-up and muffled giggling that Artie thinks he might need a new name. Arthur has never felt right and now Artie isn't feeling like enough. He doesn't mind it but he doesn't love it. He needs a name that fits him completely and he ends up scouring the library in search of it. Eventually, he finds his name inside a dusty book on Greek mythology.
Artemis.
It's perfect because not only does it allow him to keep the nickname Artie but it he's heard of it being both a boy's and a girl's name. Artie doesn't mind being a boy but he hates that being a boy means he's apparently not allowed to enjoy stuff like dresses or the colour pink. Also, the Goddess Artemis is super awesome and maybe, if he takes the name for himself, he can be that awesome himself.
Artemis doesn't let anyone know of his name change but now, whenever someone calls him Artie, it's Artemis they're addressing.
When Artemis is 12, he decides he's done hiding. He doesn't want to just be Artemis in secret, with his love of all this manly and girly hidden, he wants everyone to know. So, when the bell rings for a mission, he runs to his room and switches his trousers out for one of Allison's skirts, haphazardly adjusted since she gave it to him. He ends up being the last one to the door because of it, and had intended to just rush through to the car, but he shouldn't have underestimated dad's eagle eye. Reginald stops Artemis in his tracks with an arm extended across the doorframe.
"What are you wearing Number 4?" Reginald asks sharply, "Are you trying to make us a laughing stock?"
Klaus has felt embarrassed before, but the look of pure disgust Reginald is regarding him with makes him want to throw up a little.
"No," he answers feebly.
"Then why are you wearing a skirt? You have trousers, Number 4."
"I-I just…I wanted to wear it," Artemis says with a trembling voice. "And, and my…" he wants to tell Reginald his name is Artemis, take courage from his namesake, but he can't. His throat has closed up.
"You're what, Number 4? What can possibly say that will make you less of an utter disappointment than you already are?"
Artie has fully lost his voice now and his gaze sinks down to his shoes, already scuffed with dirt.
"Nothing. As I thought. You will go back to your room, Number 4, take that skirt off and think about your actions. I will not have you embarrassing the academy."
Artie's head snaps up. "But, the mission…"
"Can be completed without you. Now, go. Hurry!" Reginald snaps and Artie runs to his room. Hiding beneath the covers, without his skirt but unable to put his trousers back on, Artie decides that maybe he's not an Artemis after all. He's not brave or heroic. He's a disappointment. An embarrassment.
Artie never claims back Artemis, even though as he gets older, Reginald's grip over him loosens more and more. He still joins in on the missions, for the public's sake more than anything, but otherwise, he doesn't train, he's out of the house when he can, and he wears whatever the fuck he wants. He's 16 now and gearing up to leave home officially soon. He knows Diego's planning it too and plans to do it the day after. Dad'll be so wracked up with grief losing his precious Number 2, he'll never even realise Artie's gone.
He's been getting drugs for at least a year now and frequenting the club, Indigo, the past few months. He's not even needed a fake ID. Turns out even being the least useful member of the Umbrella Academy has its perks. He knows the regulars by now, which is why he notices it when there's someone new, someone who apparently has their eyes on Artie.
He's young, Artie can see that much under the dim, multi-coloured lighting, maybe even as young as he is. He's also hot as fuck and Artie gravitates towards him, high on the atmosphere, and on the white substance currently residing in his pocket. It's the first time he's wanted more than a break from the ghosts and a good dance, and his pulse picks up with excitement. He's known for the past few years his sexuality is as fluid as his taste in clothing and Artie thinks it's about time he put it into practice.
"You're pretty," the guys says as Artie begins dancing with him and he preens under the praise. Wearing a mini skirt, crop top and probably way too much eyeliner, he's heard the word thrown at him as an insult more than once. This guy, he's serious. He likes what he sees.
Well, the sentiment is most definitely returned.
"You're not so bad yourself," Artie replies, welcoming the hands that clasp his waist.
They dance the night away, getting closer and closer with each song until Damien's lips run along his neck and Artie tangles his fingers into wavy brown hair. He's had his first kiss this night, along with his second, third and…well, there got to a point where he just had to stop counting.
"You've still not told me your name," Damien murmurs in his name. "Keeping it secret? Are you afraid of me?" He grins and Artie laughs. If only Damien knew just who he was.
"Mm, why don't you give me one?" Artie suggests. He's been wanting a new name for a while name. A new name that fits in with the life he wants for himself, and he thinks here, riding high on a unicorn with a guy who's called him pretty and given him his first kiss, now is the time to get it.
"Hmm, Gertrude," Damien snickers into his collarbone and Artie whacks him playfully on the arm.
"Try again," he says with mock seriousness and Damien relents, pausing in their dancing to look into Artie's eyes.
"You're Klaus," Damien decides boldly and Artie tries the name out.
"Klaus…Klaus" he repeats. A grin forms on his face. "I like it."
"Well then Klaus, how about we get out of here then?" Damien proposes and how can Klaus do anything but follow.
Klaus never feels the need to change his name again.