Wishcraft.

Brett is a high-school outcast who doesn't run with the in crowd, unlike Samantha, the cheerleader he has a desperate crush on. Then one day, he gets a parcel in the mail -- a totem with the power to grant his deepest, darkest desires. Brett wishes for Samantha to love him, and she does, although after a while her affection starts leaning toward obsession. Then murders start occurring in the school, which Brett gradually starts to connect to the totem.