Semi-Autonomous: Metousiosis is a Greek term (μετουσίωσις) that means a change of ousia (οὐσία, "essence, inner reality").
Neale (History of Eastern Church, Parker, Oxford and London, 1858) as follows: "When we use the word metousiosis, we by no means think it explains the mode by which the bread and wine are converted into the Body and Blood of Christ, for this is altogether incomprehensible [...] but we mean that the bread and wine are changed into the Body and Blood of the Lord, not figuratively or symbolically, nor by any extraordinary grace attached to them [...] but [...] the bread becomes verily and indeed and essentially the very true Body of the Lord, and the wine the very Blood of the Lord."
[1] Philip Schaff wrote in his Creeds of Christendom: "This Synod is the most important in the modern history of the Eastern Church, and may be compared to the Council of Trent.
[4] Nikolaj Uspenksij appeal to Church Fathers who, when speaking of other doctrines, drew analogies from the Eucharist and spoke of it as bread and wine, but as having also a heavenly nature.
[5] Some Eastern Orthodox theologians thus appear to deny transubstantiation/metousiosis, but in the view of Adrian Fortescue, what they object to is the associated theory of substance and accident, and they hold that there is a real change of the bread and wine into the body and blood of Christ.