See You Soon (Scarred Executioners #1) by Lexie Axelson

Ari Alvarez,

a recent nursing graduate student who is no stranger to the military lifestyle. She's naive, fearful yet motivated after the passing of her older brother. She's entering a new chapter in her life where she has to adjust without her best friend and start a career that mentally and physically challenges her. Meanwhile, she's battling the unknown gnawing details of her brother's death and the grief that follows her.

Danny Rider,

Operator Grim Reaper is a Navy SEAL who lives a very selfish, career-focused life and he likes it that way. He is only responsible for himself and no one else. He's a lethal killer, with demons always looming inside of him due to all the trauma of constant deployments. Yet, when he meets Ari she's both damaging to his addictions and the halo he needs.