Resonance - Dianne J. Wilson - Bog

Kai was born with the ability to see brokenness and to fix it. This ability has a name: Affinity. Saved from death and freed from the spiritual realm, all Kai wants is a chance to go back for the friend he left behind. But his simple rescue mission is sabotaged and all the broken, homeless kids from the OS are sent back into the spiritual realm with him to be recruited, marked and re-purposed by the enemy. Cut off from the source of his ability, Kai is plunged into a desperate struggle against time to rescue them all before their blood is on his hands.