Tokiomi's wife, Aomi, is NOT Kariya's sister, she's a childhood friend that he's in love with but she never reciprocated his feelings.
BetheSOUL
2021-02-12 10:27:17 +0000 UTC
It's more than a set of rules, it's part of their culture (like arranged marriages, etc.). And he didn't know he was sacrificing her, he thought he sent her off to become a full fledged mage under a different name. He didn't know about Matou's creepy worm thing
BetheSOUL
2021-02-12 09:47:17 +0000 UTC
That's tokiomi for you. He will happily sacrifice once child if it means the other can inherit the family magic. It's definitely cruel but mages have their own set of rules.