The Fallen One by Brittney Sahin

Five years ago, a phone call forever changed my life as I listened to my wife being murdered half a world away.
Going rogue from the CIA, I became a man feared by everyone as I sought vengeance. Lies she’d told and secrets she’d kept, pushed me over an even darker edge.
With nothing to lose, I became unstoppable. A devil among men. Until justice was served, or so I’d thought it’d been . . .
Working alongside a team of veterans, trying to find my way back to the man I’d once been, another life-altering call came, drawing me back to the dark world I’d left behind.
The assignment should’ve been straightforward. Rescue a brilliant scientist working on a classified government project and save the nation from an attack while I was at it. But nothing in my life was ever simple.
When the missing scientist turned out to be the same off-limits woman I’d been obsessing over for months, saving her life was the easy part.
Not corrupting her in the process was the challenge. Especially when that gorgeous woman, innocent and untainted by the evils of the world, begged me to do exactly that.
Our past was complicated. The chemistry between us, undeniable. The desire to claim her as my own and never let go, unbearable.
My team may have been up against our most formidable threat ever, but there I was about to do something I never did. Lose my control.