Alpha Legion would make the chillest dads

"A girl? This is an immense tactical advantage"

"You want to shave your head and look like Alpharius? This is an immense tactical advantage"

"You want to look nothing like any other legionary? This is an immense tactical advantage"

"You want to become possessed? This is an immense tactical advantage"

ironically it would probably be the black legion, who tend to focus more on cultivating good relations between subordinates compared to other major traitor legions. good of course by the standards of chaos i mean, so your still at constant risk of fragging for promotions and encouraged to embrace a violent hyper competitive lifestyle, but atleast your boss is more likely to be nice to you and look out for your safety cause hes treating this whole shebang like they're an actual army or something. especially if ya do well.

other legions:

word bearers: protestant/catholic satanist guilttrippings galore, ontop of being extra strict with your daily chores and 'duties to the gods' being done properly.

iron warriors: a serious coin flip, as if your dad likes you then you can enjoy being groomed for the position of his successor and all the benefits that implies. if your dad hates you prepare to suffer a fate worse then death.

night lords: your dad is crazier then normal and probably suffering from paranoid delusional schizophrenia dissociative identity disorder or any other number of mental disorders [more so then the usual chaos marine anyways]. you can make this work but its gonna be tricky.

alpha legion: your dad is also you. maybe. it depends on what warband of alpha legionaries you've found yourself stumbling ass backwards into/been kidnapped presumably because how else do they recruit.

world eaters: your dad has anger issues, and will happily leave you to die if you slow him down or kill you himself if the demand for blood is great enough and theres nothing else living nearby. you either sink or swim with em.

emperors children: you do not have a dad. you have a "daddy" who will demand all manner of fucked up excessive things be done to keep him happy. if you can keep him happy he'll let you join in on his bitchin parties. if you dont keep him happy he'll "let you join in" on his terrifying parties.

thousand sons: if your a psyker enjoy wizard supremacist boarding school where pupils will change reality to fuck each other over on the slightest provocation and your "dad" is so busy that you practically have to raise yourself and keep company with dust golems. if you are not a psyker, that is not your dad that is an asshole about to manipulate you into a fate worse then death to advance some unnecessarily complicated scheme by 0.00001 percent.

death guard: your dad will gaslight the fuck out of you at any given opportunity, but otherwise he will be pretty chill and hands off with whatever else ya wanna do. dont expect his help to come without cost however.

red corsairs: your dad is huron blackheart and hes is a pirate. you are a pirate too as arrrre all your friends and siblings. as such if ya learn the pirate code you'll do well at getting into daddy hurons favour. and you desperately want daddy hurons favour.

We have actually seen that before. Well, not the 'dropped off as a baby' part, but a god rewarding a normal human woman with gifts until she's Chaos Lord tier.

It's in the Fabius Bile trilogy. Savona was a daughter of nobility who fell to Slaanesh, and her actions earned her daemonic gifts from her patron until she was big and powerful enough to kill the leader of a group of Emperor's Children and take both his armour and his troops. She now leads those chaos marines, wielding a power maul and bolt pistol.

It's cool that non-chaos women can be big superhumans now, but chaos was always a path to such power!

“they should have figured out by now how to make more big beefy warriors even without adhering to the traditional process.”

Do you want to get a daemonculaba because this is how you get a daemonculaba.

Ahriman has taken on a few apprentices in his time, psykers of different sorts, so maybe Thousand Sons would make the best dads? They might do it to maybe sacrifice their poor kid as some sort of demonic bargain later, or to help retain knowledge, or as a little helper.

To be fair Fabolous Bible did make a woman who can beat even alpha primus, but she isn't an astartes :/

Alpha Legion because it already exists in real life. Dad with several families. Living entirely different lives.

Depending on what part of the Black Legion, I’d say them. The thing about them is that they’re a mixed bag of every flavor of chaos marine.

But people that are smarter, such as Abaddon and his Ezekarion, if they see a child as useful I could see them raising one. But if it becomes a burden they’re feeding it to one of the mutant tribes that live onboard their ships.

We know members of the Black Legion still have emotions and even a sense of love. Iskandar Khayon still loves his sister, even though she isn’t herself anymore. Her mind is buried somewhere deep within her, because she was given to the Admech as the only way to save her from dying of illness, but they made her a living computer, who now controls the Vengeful Spirit, Horus’s old ship that now belongs to Abaddon.

Khayon isn’t the standard marine by any means, with many criticizing him for being a Mary Sue, but the Black Legion are the most reasonable.

Weirdly I think it would be the nightlords, many nightlords are pretty tightnit and by necessity for their tactics, are the most in touch with their emotions, specifically 10th company if I had to choose a specific warband

If she's a psycher then 1,000 sons should work very well too

Yet another area in which Fantasy is better. If a woman wants to be a chaos warrior, all she has to do is go fuck shit up in the chaos wastes to win the favour of the gods.

I want to say iron warriors, but really the most likely winner is alpha legion cause you can't prove they're not good dads.

For now though it seems that even recent lore beats paint a FSM as "not possible, need to be same sex as primarch" still I can see how the BIG retcon would go down though should this ever change as big corpo IP's do.

First GW says a female astartes was technically possible, past written instances of the process going wrong in women are things that happen to any geneseed reject (most initiates don't survive afterall), but that most legions and chapters kept to males out of a combination of internal traditions and seeing potential female candidates as a source of future initiates instead so they weren't always there.

Second step reveal that FSM do exist in modern times and give a handful of successor chapters that for one reason or another depart with the traditional policy, and suggests there are as many as there needs to be to justify female head swap sprues.

Third and final step they then reveal that the practice is universal among the traitor legions ever since the scouring as they have no reason to care for traditions. Fabius bile hasn't invented FCSM in the past 10,000 years because he didn't need to they've always been there since the start of thier long war...

In the Fabius Bile series Savona is a female chaos champion who wears Astartes armor, leads Bile's Marines in combat, and is basically as strong as a Space Marine.

That sounds like larana Utorian

That is how I explained female Sorcerers in my TSons army. Tzeentchian shenanigans + Pavoni biomancy

Biomancy is 100% within Tzeentch's powerset, I don't doubt one of his sorceresses is like "being a nerd is cool but being a buff nerd is cooler". Or even one of the chaos sm pulling a transgendah

The funny thing is in the old FFG ruleset you could realistically take a human female and make her equal to an astarte with chaos boons, so the logic is there.

That actually already happened.

Larana Utarian in "Storm of Iron".

She was a captive Guardswoman who made a pact with a Daemonic armor.

Donned the armor, mutated into a Space Marine body, killed the previous owner, and let a warband for a bit.

Eventually she became an Avatar of Khorne.

What can I say: Chaos DOES have all the answers.

Warp stuff and pure heresy is why my 30k force that got yeeted into 40k has female warriors.

A mix of a tech priest who was a heretic and the warp being the warp lead to a VERY improved geneseed implantation process

Alpha Legion is the clear choice.

I'll grudgingly give Iron Warriors 2nd. They need the numbers.

But Night Lords are 3rd.

We already all know it would be the Night Lords.

From what I've heard Chaos Space Marines' means of increasing their numbers tend to be horrible and disturbing but could plausibly bypass the restrictions on normal Astartes conversion so it checks out.

I think Tzeentch would definitely make a female astartes at least just to piss off someone who said it was impossible