Zack Wilder is an agent with the FBI.
I am aware the the fact sheet above lists the Fulcrum as the organization for which he works and that is correct but when we meet him he is a G-Man and he works hard to make sure no one learns of his connection to the other group, assuming those people even knew of its existence.
"The Fulcrum [was] a clandestine organization that had existed beneath the surface of society for hundreds of years. An organization created to seek balance in a world that teetered on the edge of chaos. Over the centuries of their existence, they'd brought the world back from many situations that would have resulted in irrevocable harm to the planet or to mankind itself". Obviously secrecy was vital to the silent backstage work that they quietly did. More on his life in it later.
As we learn immediately in the first recorded adventure, he is a stickler for following standard protocol. That proves annoying to some colleagues, especially his most recent partner, Anna, but that was not how it always used to be. According to what we are told, in the past he "had a habit of breaking the rules. Certain interested parties had been worried the habit would get him killed". Now he strived to follow that advice but in truth, he is nowhere as stiad as many see him. Take for instance the knife he wears in a sheath around his ankle - very much not protocol - and has a deadly skill with it tossed or held. And throw in his exceptional martial arts abilities that he will call upon as needed.
Wilder is just two years into his time with the Bureau, hence he is still referred to as rookie on occasion. Prior to that he was in the U.S. military. As a former Army mate of Wilder put it, "We were a special ops unit, made up of men selected from various forces. Zack and I both have Army Rangers backgrounds, but there were Navy SEALs and Air Force too. We were called in when a job needed doing. Usually one nobody else wanted. Often counterterrorism but not solely. We worked all over the world."
And before his time in the Rangers and thus part of that elite task force, Wilder had been with the Fulcrum. From the day he was born it had been part of all his life and and his family before him. "At the age of four, he'd been handed over to their training center by his parents, and he'd never seen them again". His official dossier would say that he was orphaned at an early age and had been raised in the system. In a very odd way, that was true. In truth, his childhood was spent learning how to be the most efficient, and deadly, operative he would be for service in the Fulcrum. He would find that he was very good at it.
He also found that while "the Fulcrum's objectives were good-to find balance in a world teetering on the edge of chaos-their methods were often ruthless". Wilder definitely believed in the Fulcrum but as we follow his service in the FBI and in the Fulcrum, we will watch him learn to always be a bit wary.