The Sparks by Kyle Prue

Honor does not bend. A will of iron does not break. Victory lies within the ashes.

The Vapros, the Taurlum, and the Celerius: three dynasties bound by an ancient promise, and given superhuman abilities to protect the city of Altryon from the dangerous world beyond its walls. The Vapros have the ability to teleport and turn their enemies to ash, the Celerius have super speed and the ability to heal from any wound, the Taurlum have skin like steel and godlike strength. Centuries of petty infighting have turned the families against each other, resulting in a secret war. A powerful emperor now rules over all, as the families have weakened by massive casualties.

Sixteen-year-old Neil Vapros desperately wants to become an assassin, to please his hyper critical father. After failing his first mission, Neil learns that a sinister new force has awakened. This mysterious new power threatens to shatter the established order and threaten the lives of everyone in Altryon - regardless of their family name or allegiance.