Shadow of the Sword

From publisher blurb:

Shadow of the Sword provides alternate and brutal combat guidelines for the 5th Edition of the most famous fantasy roleplaying game of all time. It is an option for players and GMs that want deadly and tension-inducing scenes, like those found in shows like Game of Thrones and Vikings, in their games. These guidelines also help even the battlefield between martial and magic-using classes. That all adds up to a new, unique and visceral 5E gaming experience without having to learn an entirely new game.