Fearless Vampire Slayer is an achievement in The Witcher 3: Wild Hunt and requires one to complete Contract: The Mystery of the Byways Murders by killing Sarasti. As such, this is a missable achievement.

Tips

• When talking with Byways' villagers, you must push for more information to be able to explore the tunnels. If you say it's not your concern or decide not to press for details, you won't be able to investigate and thus find and kill the ekimmara.