Hunters Mark- fanfic (no black widow spoilers)

Alec's family are all hitmen, hitwoman since 1934. Following a mark his great great great grandfather began to use, calling it the hunters mark each son or daughter is to follow the same mark. All of them follow 1 rule, only kill if your getting paid. Each of the family each earn over 1.5 million before they die.
But Alec was smarter and stronger. After his countless stealth murders he is now known as The Silencer, wearing a bulletproof trench coat and bullet clothing. His ability to predict and counter attacks out do anyone. Killing any targets with little to no effort.
But what if his new target is Yelena Belova. One of the fastest and strategic fighters. But when they meet in Paris, what happens when feelings spark between the two.
[Yelena Belova x Male oc!]