Try reading and understanding what epiklesis means. The change is made by the Holy Spirit.
That being said, in the RCC the epiklesis has been somewhat diminished, but it is there. In the Orthodox Church, the epiklesis is the crowning point of priest's supplication, not magic. The "magic' is done by the Holy Spirit.
From the Divine Liturgy of Saint John Chrysostom:
People: We praise You, we bless You, we give thanks to You, and we pray to You, Lord our God.
Priest (in a low voice): Once again we offer to You this spiritual worship without the shedding of blood, and we ask, pray, and entreat You: send down Your Holy Spirit upon us and upon these gifts here presented. And make this bread the precious Body of Your Christ.
(He blesses the holy Bread.)
Deacon (in a low voice): Amen.
Priest (in a low voice): And that which is in this cup the precious Blood of Your Christ.
(He blesses the holy Cup.)
Deacon (in a low voice): Amen.
Priest (in a low voice): Changing them by Your Holy Spirit.
(He blesses them both.)
Deacon (in a low voice): Amen. Amen. Amen.
So as you see, the power is not in the priest. The priest is simply doing his priestly duty to which he was called and ordained, to ask God.
The oldest liturgy goes back to St. James in Jerusalem. You figure out the year. I guess the world had to wait for almost 2,000 years to be told that St. James also believed in "alchemy."
To say that a priest is some sort of a magician and alchemist is shamefully ignorant to put it mildly.
Here's the epiklesis from the Divine Liturgy of St. James:
"Have mercy on us, Lord God, the Father, the Almighty. Have mercy on us, God our Saviour. Have mercy on us, O God, in accordance with your great mercy, and send forth upon these holy gifts, here set forth, your all-holy Spirit, (bowing) the Lord and giver of life, enthroned with you, God and Father, and your only-begotten Son, co-reigning, consubstantial and co-eternal, who spoke by the Law and the Prophets and by your New Covenant, who came down in the form of a dove upon our Lord Jesus Christ in the river Jordan, and rested upon him, who came down upon your holy Apostles in the form of fiery tongues in the upper room of holy and glorious Sion on the day of Pentecost. (Standing up) Your same all-holy Spirit, Lord, send down on us and on these gifts here set forth,
(aloud): that having come by his holy, good and glorious presence, he may sanctify this bread and make it the holy body of Christ,
People: Amen.
Priest: and this Cup the precious blood of Christ,
People: Amen.