Jesus is NOT reincarnated. He was Incarnate; God made flesh. Jesus was both thoroughly human and Divine in the same person. In the celebration of the Eucharist, the host/wafer’s substance is changed into the Body and Blood, Spirit and Divinity of Christ though the host/wafer retains the physical appearance and properties. The entire body gathered before the altar goes back to the Last Supper and Christ fills the priest with His Spirit. When the priest says, “Take this, all of you, and eat of It, for this is my Body, which will be given up for you” he doesn’t mean to eat his (the priest’s) body. Christ speaks through the priest those words just as Jesus spoke those words during the Last Supper.
But, alone, the priest cannot call Christ down and force Him into a host/wafer; that would be blasphemy! God is God, after all! The priest does God’s bidding and in doing so Christ becomes incarnated in the host/wafer.
To a casual observer, the host/wafer appears just as a bit of formed flour and water just as Jesus might have appeared to the Apostles as a normal man over 2,000 years ago. Jesus kept telling them over and over what to expect but they kept missing the point until after the resurrection and the descending of the Holy Spirit upon them. Since then, the Last Supper has been re-enacted millions or billions of times and each time, Christ is present in the Holy Eucharist. Truly emmanuel: God is with us!