1. St. Cyril of Alexandria called the Blessed Holy Virgin Mary the [[Theotokos]], Mother of God, not mother of the human nature of Christ. From the soteriological viewpoint, if only an ordinary man without a trace of sin (and not the Incarnate Logos) died on the cross, then this would not be enough as an atonement for the (infinite) sin of mankind against the infinite God.
2. Copts believe in '''two''' natures "human" and "divine" that are united in one "''without mingling, without confusion, and without alteration''" (from the declaration of faith at the end of the Coptic divine liturgy). These '''two''' natures "''did not separate for a moment or the twinkling of an eye''" (also from the declaration of faith at the end of the Coptic divine liturgy). In fact, at the time Christ died on the cross, His human soul left his human body, but His divine nature remained united to His human soul and human body.
3. The Non-Chalcedonian, Oriental Orthodox were habitually represented by their Chalcedonian opponents as denying all reality to the human nature of Christ after the union, but this is definitely not true and was never the case.