Here's another one. It's a weird idea that stroke me once when I thought about why Sesshoumaru could be taking Rin with him. The fic is playing right after Rin has been kidnapped, but that comes out anyway.
Addicted to Serenity
Sesshoumaru sat on the ground, leaning against a tree. He watched Rin play in the meadow, uselessly picking flowers like she often did.
He had been careless enough to let her get kidnapped, and the human boy had almost killed her. She was humming now, another occupation she liked to pursue. Every human child would be scared after only a day, but she wasn't.
Yesterday, Inuyasha and his group had met Rin for the first time. By now, they were surely contemplating the reason why he was caring for a little human girl. He was sure that Inuyasha hadn't found out what even he, Sesshoumaru, had only smelled when Rin had been bitten to death, the smell of her blood thick in the air. Their father's blood was cursing through her veins as well, although weakened over many generations.
Rin came back with a bunch of flowers. "Here, Sesshoumaru-sama," the girl said, smiling, presenting the flowers to him. She would never lose that smile as easily as a mere human.