There was a fic i read a few months back that was terribly interesting.

Sesshomaru came to ask kagome (or maybe just the group in general I can't remember) to heal in of a malady that's plagued his lands. She travels with him tot he castle where everyone is suffering from it, even sesshomaru eventually. but she learns she can purify the sickness with her power, and gains his gratitude. What's this one called?? Anyone know?

Sounds like Second Alliance by Imani Joain
dokuga.com/fanfiction/story/8948/1?author=18611
A new threat has breached the peace left in the wake of Naraku's defeat. This time, it will be Sesshomaru who must propose an alliance to defeat an enemy he has no experience with: a death that claims humans and demons alike. Only his half-brother's strange miko truly understands the danger, and she is the key to conquering it. Originally posted on fanfiction.net. Revised edition here. 2nd Semi-annual 2013 Dokuga Awards: Best Canon, 1st Place; Best Kagome Portrayal, 1st Place; Best Sesshomaru Portrayal, 3rd Place; and Best Darkfic/Horror, 3rd Place. Nominated for Best Romance. October 2014 Feudal Association Awards: 1st Place Best Drama Fiction.

Rated MA! No YIM!

Thank you very much!