Mixed episode happens to me when I feel both high and low. But the high happens to be an agitated and angry one. Which is why it is called a mixed episode since I feel both negativity and manic high.
It was just last night I had a mixed episode incident which was triggered by lowering a very crucial medication in my cocktail. I felt the need to scream and shout and cry at the same time. At every corner, I felt I was being attacked by flaming arrows by evil ones.