The Eucharist slanders the Jews
Catholics go as far as to turn the ritual of taking bread and wine as emblems of the body and blood of Jesus, according to his supposed command, into something amazing. They think the wine really becomes his blood. If the ritual is evil, going that far with it to turn it into a religious pageant and a celebration of the mystical is compounding the evil.
Now to Jesus in Matthew 23:34–36 where he rages against Jewish leaders. Remember leaders did not mean leaders only but their assistants for no leader is an island.
He focuses chronologically on the ancient martyrs of the Hebrew Bible—spanning from Abel in Genesis to Zechariah in 2 Chronicles.
He tells the Jewish leaders he blames them.
The Church weakly says he didn't mean all Jews. It is only saying that and has no wish to convince you. It has to admit that he could have. That would be vile but he did. The men he shouted at were innocent of those crimes. They were not named meaning all Jewish leaders were getting blamed. And the people made them leaders so he hints that they are reflected in the leaders they have.
The gospels indicate that Jesus didn't need supernatural knowledge to see he would die tragically himself. He surmised that his own death would crown this very history of rejected messengers. He saw himself in that vein of blood running through Jewish history. He may have mentioned Zechariah - but as he had not been murdered yet he would have had included himself. This is what he was getting at in the Eucharist. He said the cup was his blood of the covenant.
The vocabulary Jesus uses in His condemnation explicitly mirrors the language He uses later at the Last Supper:
In Matthew 23:35: He condemns the shedding of "...all the righteous blood shed upon the earth..."
In Matthew 26:28 (The Last Supper): he establishes the Eucharist, saying, "For this is my blood of the covenant, which is poured out for many for the forgiveness of sins."
By using the terms poured out and shed (translated from the same root concepts in Greek), Jesus directly links His own impending death to the legacy of the ultimate righteous sacrifice. He wasn't just predicting a historical pattern; He was identifying Himself as the climax of it.
Arguably if he was saying that by some mystery the Jews were to blame for the bloodshed though according to the evidence they could not be, then by some mystery those who drink the cup of his blood are connected to his blood. Blood brings blame versus blood brings forgiveness.
Just a few verses prior, in Matthew 23:32, Jesus tells the religious authorities to "Fill up, then, the measure of your fathers." Commentators widely agree that this "filling up" refers directly to them orchestrating His own bloody demise.
The Church would say, "He sensed what was coming, and by willingly offering his blood, he transformed a history of tragic murder into a gift of redemption celebrated in the Eucharist." But to offer blood to God in a context of blaming innocent men for centuries of murders of holy persons is blasphemy - unless God himself is a villain.
People drinking the wine are honouring and representing the evil slanderous
meaning of the blood. The cup stands for blood that the Jews can be blamed
for.
Matthew even lies that the Jews cried that Jesus should die unjustly
and that they want his blood on themselves and their children...
Jesus linked his "this is my blood of the covenant" reference to how Moses sprinkled the people with sacrificial blood telling them it was the blood of the covenant God made with them. Jesus strangely did not think of using the Passover Lamb blood and saying it was his blood and sprinkling the apostles. But the link is there. But Matthew compensated for that. He made up the report that the Jews called the blood of Jesus on themselves and their children. The sprinkling motif seems to be there.