I would avoid buying this DLC. I got mine from pre-ordering the game. The Akenash Dagger will dissolve a NPC once killed. However, Styx: Shards of Darkness - The Akenash Set в Steam
: Increases the duration of clones before they disappear. Styx: Shards of Darkness – v1.05 DLC
: An old, sturdy blade covered in deadly acid. I would avoid buying this DLC
: Enemies killed with this dagger dissolve instantly, removing the need to hide bodies. Styx: Shards of Darkness – v1.05 DLC
: The blade is "dull," meaning you cannot perform muffled (silent) kills. Patch 1.05 and Versions
: The DLC was originally a pre-order bonus but is now available for purchase on platforms like the Steam Store for approximately $2.99.