If Genesis is the catalyst for a new beginning, then what has to end?

She is called Genesis. 

After nearly dying, Tristan wakes with enhanced senses and abilities, beginning her evolution into something more than human. Tristan's once-normal life becomes chaotic, frightening, and complicated by Audley Morgan. Audley exudes ominous intensity that warns of violence and destruction. Though Tristan can sense how dangerous he is, she can't deny his compelling charisma.

He is called Cleric.

Even though killing was Audley's gift, he thought he was done with bloodshed and body counts - until Tristan Glass comes into his life. Tristan is intelligent, alluring, and the only human carrier of an ancient genetic legacy, which makes his attraction to her annoyingly problematic.

The time for judgment has come. 

With Tristan's awakening, an archaic war between two factions fighting for control of humanity has begun anew, with her at its epicenter. What fate is in store for mankind? A choice between mercy and annihilation must be made, and that choice is Tristan's alone.

Parts one and two from the Return of the Aurora series. 

Some descriptions of sex and violence.