You can choose the game’s difficulty level: Normal or Easy. This choice can be made before starting a Memory or even during play.
Apply the game’s regular rules. For each 100% Sync won when playing through a Memory entirely in Normal Difficulty, stick the red version of the 100% Sync in the Diary of Memories.
When attacking Enemies, ignore the Retaliation rule for Crossbowmen only. However, for each 100% Sync won by playing through all or part of a Memory in Easy Difficulty, stick the gray version of the 100% Sync in the Diary of Memories.