Splinters of Your Soul

"Nii-san," Sasuke asks him, "what is a soulmate?" / Itachi vowed the moment his brother was born to protect him no matter the cost. Sasuke vowed, when he witnessed his brother standing over their parents bodies, to hunt him down and kill him. Finding out they are soulmates changes nothing at all - but at the same time, it changes everything. [ITASASU]