The term mediant can also refer to the relationship between two triads, not just the III (or iii) chord of whatever key you're in. For example a diatonic mediant relationship exists between V and viio, and a chromatic mediant relationship exists between V and (b)VII. But I'm talking about chords that have a chromatic mediant relationship with the tonic of a minor key, specifically when the III and VI chords in a minor key have their thirds lowered to make them minor. Thanks for replying though.