Echo (Teen Wolf)

Kylie and Erin have been best friends since pre-k. They were normal high school girls until Kylie got bitten by a werewolf. Erin however stayed human but the two still stayed close. When Kylie joined Derek Hale's pack her whole world changed, rival packs, other members of the pack taking interest in her, and blood lots of blood. Erin on the other hand falls for the grade's nerd and Scott McCall's best friend Stiles Stilinski a fellow human. Only Kylie knows about her little crush and swears to tell no one. The two form a friendship with Stiles, Scott, and Isaac Lahey another wolf in Kylie's pack. As their friendship goes on, more feelings arise. But the relationship is utterly and tragically one sided. As their lives go on and times get harder, Kylie and Erin will still be best friends. No matter what happens, they will be together forever. Even when they're alone, and only their echo fills their minds. They know they can still count on each other forever.