Sesshoumaru:
A cold-hearted demon that cared for nothing but power.
Despises the human race due to the shame brought on his family.
He has no weaknesses and no flaws.
He was a perfect killer.
Rin:
A kind-hearted little girl with a hyper attitude and a bubbly personality.
Have many fears, of wolves, of human men, of thunder and lightning.
She was weak and defenceless.
She was nothing but a weak human child.
This all changed when their two paths met.
Sesshoumaru's cold heart was melted by the kind little girl.
Sesshoumaru came to accept her human like behaviour.
The human child had become Sesshoumaru's only weakness.
Rin feared no more. She knew she was protected.
She no longer had to worry about being weak, as she was defended.
She was the only human to ever melt a demons heart.