(Giovanni Dominico Tiepolo, "The Institution of the Eucharist," 1753)
It is typically very difficult to get a fully possessed person to go to Mass. As often as we encourage the person, the energumen (possessed person) feels a preternatural revulsion to the Eucharist. "K" was no exception. We could not get her to go without practically dragging her into the Church. And then, sitting through the entire Mass was painful, if not impossible.
After months of exorcisms, she was much better but getting her into the chapel was still a huge struggle. Finally, we finally were able to schedule a private Mass for her, her father, and uncle. For three days before the scheduled Mass, she manifested almost constantly. The demons knew what was planned and they went ballistic.
They manipulated her and everyone else, trying to sabotage the event, but no one budged.
When the day came, her family, not-so-subtly, all but dragged her into the chapel. She was seated between two large family members who kept her in place. Then the Mass began. As the Mass progressed, she kept yelling, "You're killing me!" She said her stomach hurt and she felt nauseous. She heaved many times. We had a bucket nearby and she wretched a white foam into the bucket. When the Gospel was read, she reacted violently. (I must admit it was difficult for me to concentrate.)
Then, it came time for communion. After much coaxing and finally a command from her father, she opened her mouth. As I approached with the Sacred Host, she screamed, "You're burning me!" I put the host into her mouth. She thrashed and tried to spit it out, but her father held her mouth shut. Later, she said the Host tasted like "ashes."
After the Mass ended, she returned to herself. She said the demons were gone (at least temporarily) and she was at peace. She laughed, joked and smiled.
Satan, unintentionally, witnesses to all that is holy. He writhes when sprinkled with holy water; he cringes at the sight of a blessed crucifix; but he positively screams when coming in contact with the Eucharist.
We, for our part, also witness to the sanctity of the Eucharist. We genuflect in front of the reserved Eucharist in the tabernacle; we adore the presence of Jesus during Eucharistic adoration; we receive the Body and Blood of Jesus at Mass with great reverence.
As St. Thomas wrote: How blessed we are to receive the "bread of angels!" (Panis Angelicus)