Another case is that while anger is still continuing, one can sense the absolute non-existence of real anger simultaneously. This is rather difficult for someone who has not yet attained realization of emptiness to understand—how can anger continue and be nothing at the same time? It’s just self-contradictory! But the truth will only be known by those who have gained sublime realization. Although there is the manifestation of anger, the essential nature has no real substance, hence illusory like dreams. To a certain extent, this is realization of emptiness of sorts, just not of very high level. Once the true nature of anger is realized, we can gradually transform consciousness into wisdom of the Buddha and bodhisattvas. This is a very effective way to counter negative emotions.
~ Depicted from "THE HANDBOOK FOR LIFE"S JOURNEY : On The Three Poisons - How to Confront Anger