The First Contact Paradox. The Vanguard Protocol, #1

The world is living in uneasy peace, though whispers of unidentified aerial phenomena persist. Captain Mira Halden (known as Eva Rostova), a brilliant but jaded tactical officer, leads "Ghost Squad, " a covert special operations unit comprised of diverse, highly skilled individuals: Sergeant Rafe "Torque" Maddix, a powerhouse demolitions expert; Dr. Elenya Vos, a quiet but sharp medical specialist with a background in bio-engineering; and Corporal Ren Kess, an agile scout and comms expert.
In The First Contact Paradox, during a routine reconnaissance mission on a remote, abandoned research facility, they activate an ancient, alien artifact. Instead of a weapon, it bathes them in an energy pulse, granting them each unique, burgeoning superpowers - enhanced strength and durability for Rafe, rapid healing and cellular manipulation for Elenya, heightened senses and agility for Ren, and a form of tactical precognition or probability manipulation for Mira.
Almost immediately, a massive alien invasion force, the technologically superior Virex Collective (known as Xylos), descends upon Earth. Their ships blot out the sun, and their advanced weaponry devastates cities. The squad, disoriented but empowered, becomes humanity's unexpected first line of defense, struggling to control their new abilities while fighting for survival against an overwhelming foe.
The book is a relentless, high-stakes battle for survival, as they face impossible odds. The climax sees the squad, now informally dubbed "The Vanguard, " repelling a critical early wave of the Virex Collective invasion, but at a high personal cost. Victory is costly, but humanity has a new, reluctant hope, and the paradox of their first contact has forever changed them.