The Path of Fire by rmcneary

Thief. Murderer. Mage. Prince. Warrior.

Heroes.

16 year-old Sabin's plans to join the army change when he learns he is a Serien — a warrior who wields an element. With a sentient sword, he must find other Seriens. His goal: unite them into a force capable of defending humanity from the Guan, a humanoid race believed to be extinct.

His charges are a belligerent thief, sarcastic assassin, adorable mage and arrogant prince. Each with their own agenda.

Stand together or die alone.

The hero price is never fair.

http://my.w.tt/UiNb/UnS60UsDrx