(I don't really know myself... t'was inspiration of the moment.)
-It is an ancient way of bonding one person in another person's family. but I changed it a bit, i am as well her protector and as you saw in the duel, I let my life be at her mercy. I decided to bond myself to her. We are like sisters, with me being her big sister protecor... i don't really know how to explain it.-