Hi. I have been looking for this fic but I can't remember exactly where I read it from. Most likely fanfiction.net. Anyway, the story takes place after the Shikon is completed and Naraku is dead. She is sent back into the future with a sentient ice sword that possess a humanoid form. I think she becomes an archeologists in Egypt when she finds something that takes her back to the Fuedal Era during a war between Sesshomaru and somebody, which she joined and subsequently ended.

This is all I can remember. Thanks in advance.

You're welcome.

I believe it's this.

Thunderstorms and Sakura Blossoms by Lady Silq Ice
The final battle leaves little behind, how are two souls to recover from such loss? WARNING Character deaths and lemons. Complete.
Rating: MA, Universe: Canon, Status: Complete, Category: Chapter Stories, Chapters: 42

My Gosh. This is it. Thank you so much, darling.