Have you read this book?
Tainted Blood by Ferrel D. Moore might be considered a horror by some, but I would place it firmly in the camp of Dark Fantasy, despite its high body count.
The story has multiple POVs, but follows the plight of Sveta, who is a professional mercenary and a handful of her fellow Russian heavies. Early on, they are laid out to attack an old man who turns out to be an unstoppable werewolf. Nothing slows this thing down, not bullets, silver, or fire. Everything about it is uncontrollable, including its need to kill scores and scores of humans.
With the help of a mysterious girl, Sveta survives her initial encounter with the beast only to find herself guided to its steampunk tech underground lair. Once there, she learns more about the fate of the man suffering from the curse of the beast while multiple gangs of the Red Mafia close in on them.
Action and bloodshed happen at any moment as these evil and heartless Russians first manipulate and then kill anything in their path, much like the werewolf they hunt. Sveta knows she should try to escape before it becomes too late, but the intense mystery being slowly reveled becomes too much for her to walk away from.
As I said, this book is full of action, but it is also full of violence and malice. If you do not like bloodshed and evil people being evil, then it could be not to your liking. Also, even though bullets never hurt the beast, not only do people brag throughout how they are going to shoot it down, but they continue to use guns even when the twenty people they just saw getting killed had been using their guns to no effect.
However, if you love action and military style battles, this could be one for you. Despite the training and force they can bring to bear, it is all useless and they will have to figure out another way to destroy this unstoppable beast.