The Reluctant Savior. Etherya's Earth, #4

From USA Today bestselling author Rebecca Hefner A complex heroine who doesn't believe in love must choose to save the realm... Evie, daughter of virtuous Princess Rina and malicious Deamon King Crimeous, is a woman torn in half. The first centuries of her life taught her fervent lessons about pain and suffering. For ages, she suppressed her mother's noble blood, crafting a reality where she was alone and drifting.until an ancient prophecy calls to her, possibly creating a purpose for her squalid existence. Kenden has commanded the Slayer army for a thousand years.
Strong, cunning and loyal, he longs for the day Crimeous is defeated and he can settle down to build a family. Focused on conquering the Dark Lord, he's stunned when Evie makes a brazen demand that must be fulfilled before she chooses to fight with them. Although incensed by Evie's ultimatum, Kenden has never desired a woman more than the flame-haired vixen. Though she stirs his ire, he also has a deep well of compassion for the beauty who suffered so much trauma centuries ago.
Together they train, and by night their connection grows, building toward the moment when they will battle her father. But, in the end, Evie has a choice and struggles to espouse righteousness over malevolence. For, when one's worst fears are exposed, the evil is so much easier to embrace... **If you love a slightly-evil, complex reformed antiheroine, this book is for you! The Etherya's Earth fantasy romance series is best read in order although each book does have its own featured hero/heroine and HEA.