Noted philosopher Liam Kofi Bright has created a setting for his 40k army, featuring what we might describe as Effective Altruists for Khorne. While I'm not great at writing fiction, I couldn't resist having a go at a piece of my own for the setting...
Some time after the events of Childrearing...
Demelzaz, unfortunately, still hadn't gotten over herself.
Gokellth bristled, drawing her blade. "This isn't the 30,000s, bitch. We've learned to accept all who worship Khorne. And besides, you heard kalû Shammuramat at mass last week. The episcopate decided that marksman cults were acceptable worship of the Blood God, and that skull-taking, while an important sacrament, isn't mandatory for everyone. Not everyone will worship the Blood God in every aspect".
"Of course you'd listen to the liberals", Demelzaz spat while drawing her knife in one smooth motion and slashing at Gokellth, who barely parried the strike. "You know Shammuramat is one of those Honoursons, and everyone knows they're practically Khainite. Besides, I saw your son at that "pride" parade last week. Black flags as far as the eye could see, and not a drop of blood. Just smoke trails. How can you live with yourself?".
"You call yourself a worshipper of the Blood God?", responded Gokellth, dropping and going for a low strike. "The decision was clear. Those ultraconservatives died screaming in under fifteen seconds. To deny it is to deny the authority of the episcopate as Khorne's representatives in the materium. You're spouting heresy."
Demelzaz, though obviously a heretic, was younger and quicker, and Gokellth was soon bleeding from a few superficial cuts. "You're weak", she crowed, as Gokellth began to flag. "No wonder your son turned out to be an abnormal pervert."
The conversation was cut short, fortunately, when Demelzaz's head suddenly exploded. Gokellth wiped the gore off her face and looked around to see a tall, somewhat gangly figure at the far end of the street waving at her. As it grew closer it resolved into Chartak, long-rifle in hand and clad in his usual urban camo fatigues and body armour. She remembered when he first begged her for them at the armoury: she was deeply uncertain at the time, but it meant so much to him that she eventually scraped together the money to get him a set. Just gone seventeen, he was beginning to fill them out.
As he came up to her, she pulled him into a hug. "Khorne above, I hated that sanctimonious little shit. Always giving me those weird side-eyes, as though I was going to corrupt Uksatha or something", he said into her shoulder. "Thanks for letting me get a clear shot."
"That's my son. Your father would have been proud of you. Probably unbelievably confused, but proud of you. How was your session at the range?" Chartak had been instrumental in setting up one of the first firing ranges in Dur-Kurigalzu, and while they'd had to deal with more harassment than anyone would have liked, three years in it had become an established part of the city and was becoming increasingly popular among the youth.
"Pretty happy with, it all told. The new group are coming along well, and even some of the wardum are asking about joining in. We'll probably have to restrict them to small arms, but we're talking about making it happen: we are accepting, after all."
"And Uksatha? I've seen the way you look at her. Is there any chance she'll be coming along to a session soon?"
"Nah, very unlikely. She's a sword girl through and through: you should watch her with one of the hand-and-a-half blades sometime. Dismembered limbs as far as the eye can see. We did catch up for burgers afterwards though, and she is thinking about learning to handle a shotgun".
Gokellth and Chartak left the hug and fell in beside each other, heading homewards. "You'll have to bring her home for dinner at some point, you know", Gokellth said, glancing at Chartak. "You've been going steady with her for six months now, and if you want to raise children to spill blood in Khorne's name with here eventually, you're going to have to let her meet your family".
Chartak looked flustered, but nodded. Gokellth smiled. All was well.