Night Guard (Book 1)

Kurayami Mori is an ice bender, She can control ice from her "inner soul" and bring through her body and to her legendary sword, Kuari. Ren is the new bad boy, but also a fire bender. Their families are arch enemies, but they have feelings for one another, even if it is forbidden for Night Gurads to fall in love. But as the Demon lord threatens to destroy the earth, Ren and Kurayami must join forces to find the other 5 Night Guards and stop the Demon lord, before it is to late