Cloud a creature’s short-term memory making them confused as to what actually transpired. Sort of like waking up after a vague dream.
In combat, all can use skills, tactics and spells that they have used in the last round with no penalty for re-use against the target. Target will also forget hidden combatants, loose track of who is injured, who has done damage, cast spells etc.
Out of combat, the last 30 seconds will appear cloudy and will be completely forgotten after 24 hours.
This will be harder if something important happened in the time frame (from +10 to +100 in DR)