Dark Mode is a new difficulty level which will be introduced with the next patch for The Witcher 2: Assassins of Kings. It is described as similar in difficulty to the "Insane" mode while allowing the player to save their game. It also comes with special "dark mode" armor and weapons.
Difficulty level
The ‘Dark’ difficulty setting is the most demanding difficulty level in gameplay terms. Under this setting, each and every foe represents a significant challenge. In addition to raising the difficulty bar, the module includes several new sets of equipment/items that are linked through a dark legend detailed in the Journal. Once all their components have been collected and donned, the Blasphemer’s, Oathbreaker’s and Kinslayer’s outfits provide great advantages in combat. The swords included in the outfits strip opponents of Vitality while supplementing the witcher’s. However, given that they are cursed, the swords provide no benefit and harm Geralt by sapping him of Vitality as long as the outfits to which they belong remain incomplete.
Blasphemer's Outfit
Crafting diagrams can be obtained from Berthold Candeleria, the dwarven smith in Flotsam. It consists of Blasphemer's armor, Blasphemer's boots, Blasphemer's gauntlets, Blasphemer's trousers, Anathema and Ultimatum. Currently cursed effects or bonus effects for full set is unknown.
The Oathbreaker's Outfit
The diagrams for its components could be found in and around Vergen. The outfit includes Oathbreaker's armor, Oathbreaker's boots, Oathbreaker's gauntlets, Oathbreaker's trousers and two swords - steel and silver.
The Kinslayer's Outfit
The diagrams of the Kinslayer's Outfit, scattered throughout Loc Muinne. It consists of Kinslayer's armor, Kinslayer's boots, Kinslayer's gauntlets, Kinslayer's trousers and two swords - steel and silver.