Stealth takedown 25 enemies.
This trophy is missable. You can perform a stealth takedown by sneaking up on an enemy and pressing the correct button. This game relies quite heavily on approaching encounters with stealth tactics in mind, and many of the encounter areas are set up this way, so you'll mostly work towards this trophy naturally.
To help with this, you can also distract enemies or lure them away from groups, such as shooting arrows at walls or throwing bottles. You can also use smoke bombs to stealth-kill groups, and the "Serpent's Fury" skill allows you to stealth-kill two enemies at once if they're close together.
You can farm these kills via checkpoint restarts, so whenever you reach a stealth encounter with lots of enemies, repeat until the trophy pops.