Flintlock: The Siege of Dawn contains 3 Revenant Locations. Finding and killing all Revenants unlocks Cataclysm Averted trophy or achievement. There are 2 Revenants in the first map of the game, Three Peaks, and another 1 in the second map of the game, Wanderer’s Rest. Revenants are small mini-boss encounters. While this guide is intended for use during the story, all Revenants can still be found and killed after the story, nothing is missable because there’s still free-roam after the story.

Three Peaks

1. Whitebridge Horror: automatic, story-related unlock, cannot be missed. You will have to defeat the Whitebridge Horror Revenant as part of the Main Quest Battle Hardened.
2. The Deep One: found in the Mireshard territory. You can get to it by taking the north-east path from the Foglands campsite.
   

Wanderer’s Rest

1. Brimstone Terror: at the very top of the crystals at The Ravine’s Secret. The first screenshot below is the starting location to the top.
   
   

These are all the Revenant locations in Flintlock: The Siege of Dawn.