17(Demon Slayer)

An abo Au where there exist at least one village were the alphas, betas and omegas living there do not follows the typical behaviour of their second gender.

Tomioka Giyuu was born in said village were the Tomioka family was known for only having betas no matter the second gender of their spouse and said betas were always as strong as a alpha but acted similar to omegas when it comes to their pups.

When Tsukato died, she took the demon with her as she fought to protect her pup(Giyuu) and instead of the village calling Giyuu crazy and trying to send him to his doctor familiars they decided to help him but in the end they ended up asking a hunter for help(the same hunter that in canon found Giyuu after he run away) who took him to Urokodaki but the villagers frequently send letters to Giyuu even if the boy doesn't write back often.

The rest follows canon in Giyuu growing close to Sabito and then losing him in the Final Selection(if they had feelings for each other is up to the writer) but when that happened, Giyuu was sent back to his village for a few weeks to recuperate and there he met his first pups Shinazugawa Genya(an omega that had lost his family to his mother who was turned into a demon and was left by his elder brother after Genya blamed him for his mother death) and Agatsuma Zenitsu(a alpha that was travelling between villages after being kicked out as his 'fiance' abused him and lied to everyone that it had been in reverse).

Giyuu since then dedicated his whole life to his two pups and killing demons until he became a Hashira and his two pups requested to be trained at least to know how to kill a demon if they were targeted which ended with Genya becoming Gyomei's student and Jigoro decided to take Zenitsu as his student since he saw potential in him.

With two of his pups out of the nest, Kagaya feared that Giyuu would enter depression again so he pushed Giyuu to help train others that wished to become slayers which resulted in Giyuu adopting a few more pups(Aoi, Kanao, Senjuro, Muichiro, etc).

Things were going well until a few new hashiras joined the ranks(not canon ones, those had already joined but these ones will not be so good people so they can be random ocs) which didn't seem to go with Giyuu's face and treated him worse then Sanemi and Iguro did in canon.

It was due to them that Giyuu arrived late to save the Kamado family(which is a good thing...Giyuu wouldn't have survived fighting Muzan) and the guilt of arriving late and find out two pups got orphaned broke his heart even after finding out one of them had became a demon, Giyuu found it hard to try and kill her.

In the end Giyuu realized Nezuko was different from other demons so thankfully he could spare her and Tanjiro, as in canon he decides that having Urokodaki train Tanjiro was the best choice so he took them himself to see his old master but before that he stopped at his village to present his two new pups to the villagers(who like when they had met Giyuu's other pups, were happy that the traumatized beta was happy and didn't lose his essence as a Tomioka...Sanemi had no idea about this because he never visited his village after killing his mother and leaving Genya behind).

Once again things follow canon except that Giyuu appears in another mission of the Kamaboko squad and adopts Giyuu besides Giyuu and his pups being always exchanging letters.

But when Tanjiro's trial arrives, our beloved hashiras(the canon ones except Muichiro) find out that maybe they all got a type and said type would kill them if they hurt his pups in any way.

What happened? Instead of Sanemi and th eothers talking about killing Nezuko and Tanjiro it was the oc hashiras who did that and tried to hurt Nezuko but the moment one of them stabbed Nezuko's box or hit Tanjiro, Giyuu's insticts took over and he beat them up with no one stopping him as the others were in shock and couldn't believe what they were seeing.

Sanemi at that moment made the connection between he late Tomioka family of his village to Giyuu and understood that he had been lucky to have been given something to calm him down by Shinobu before the meeting or he would have been in those guys place.

Does any of this make sense? Nope, I just love stories of Tomioka adopting all of the Kamaboko Squad but most of them have in as an omega but I wanted to see it with him being beta or even an alpha besides wanting all hashiras(except Muichiro) finding themselves falling for Parent Giyuu(if he ends in a poly relationship with them, with only one of them, with another character or single is up to the writer).