That’s about as convoluted as the Catholic belief!
***
It gets simpler if you reduce it to the basics.
1: The Lord’s Supper is Jesus’ body and blood and also bread and wine, because Scripture describes it as all four.
2: The Lord’s Supper gives us even more of God’s undeserved kindness, IE grace. Not because we need more grace for salvation, but because God is loving and wants to give us grace upon grace until our cups runneth over.
It’s what we confessional Lutherans believe is taught by Scripture and everything is drawn from and can be defended by Scripture. We don’t go into that mess called ‘tradition’ by a certain OTHER denomination.
It get even simpler if we try to understand the meal as the JEWS did(do)!
Jesus was relying on the disciples understanding of just what was happening at that dinner.
Even though He had to do some explaining.
35 Then Jesus asked them, “When I sent you without purse, bag or sandals, did you lack anything?”
“Nothing,” they answered.
36 He said to them, “But now if you have a purse, take it, and also a bag; and if you don’t have a sword, sell your cloak and buy one.
37 It is written: ‘And he was numbered with the transgressors’[b]; and I tell you that this must be fulfilled in me.
Yes, what is written about me is reaching its fulfillment.”