Oro was using body-binding and Sasuke had to use pain from the stab to overcome the fear of Oro's killing intent.

Shika broke out of the genjutsu because his body melting was supposed to psyche him out and was not felt as pain so he used real pain to escape.

Mange creates a situation that is so real that the brain perceives it as what is happening.

This is similar to the matrix, or the work of a powerful telepath in X-men.