I want to say the story you're searching for is Rinku's A Debt to be Paid MA

dokuga.com/fanfiction/story/5311/1?author=8493

Hello
There was a fic I really enjoyed but I could not remember the name. I read it here on this website though, it was unfinished I think.
The story was like... Sesshomaru courted Kagome because her miko blood would help him getting a powerful heir or so. And Inuyasha had to give her up because of his blood... something like being a Hanyo will eventually kill him or drive him mad.
I remember a chapter in which Kouga challenged Sesshomaru for Kagome but he could not and he noticed their aura was really becoming one (or joining or something like that).
It was very angsty but it was so good.
I hope to find it again.
Thank you very much in advance.

Thank you so much! Best regards!