few years back in A Single Spark about an AU fanfic that started off with Kagome in her village, and suddenly her village get attacked by Sesshoumaru Kagome was only like a preteen when the story begins, and Sesshoumaru ends up raping her. When he's done with the deed, Kagome says something a long the lines of "I'll become strong and I'll kill you someday" or something. Sesshoumaru is amused by her statement and ends up taking her back with him to nurture her and see if she'd actually succeed

she gets older and becomes stronger under Sesshoumarus care and i think serves as a personal something and a concubine.

please help if anyone has any ideals

Sounds like Snow Pearl by Phoenix Blade

dokuga.com/spark/story/3344/1