This isn't exactly a missionary story, but it's also about demons and God's power over them. It's from a book called The Beautiful Side of Evil:
Quoted Text
Each person in line was instructed to have a fresh raw egg to present to Hermanito for the spiritual limpia (cleansing) which was performed on everyone during the morning consultation sessions. I had forgotten our eggs and hurried out with several others in the line to purchase them at the market across the street. I handed Daddy, Peggie and Padre Humberto their eggs, then took my place in line to wait.
When my turn finally came, I entered the dark little anteroom still guarded by falcon Ursula and waited behind the plastic curtain with one of the assistants who monitered the flow of people into the altar room. I could feel powerful vibrations emanating from that room and started to pull the curtain aside to see what was happening, but the woman quickly stopped me.
"No!" she whispered. "Keep it shut until the patient in there leaves!" The curtain is here to keep any 'evil airs' that person may have brought with him from attacking you."
"I see" I mumbled apologetically. "Is this your first consultation with Hermanito?" Her voice softened. I nodded. "Then be sure you remember not to address him as 'Pachita.' It is her body you will see, but she is not in it." I nodded again. Tom had explained that to me before. Pachita was always addressed in the masculine and as "Hermanito" when the spirit was present.
Minutes later the woman pulled aside the plastic curtain for me and I stepped in
Pachita was standing near the altar. She was wearing a short sleeved cotton dress covered by a dirty yellow satin garment that was tied in a knot at the shoulder. It was decorated with sparkles glued on in geometric designs and was worn by Pachita whenever Hermanito Cuauhtemoc was holding consultation sessions or operations. Pachita's eyes were tightly shut, one of the signs that Pachita herself, her spirit, was no longer there. Yet it was as though she saw clearly. I was later to watch her deftly thread a needle even though her eyes could not possibly have seen to do so...
I stood before Hermanito, still holding the egg in my hand. He placed both hands on my shoulders and, in a voice much deeper and gruffer than Pachita's own, commanded, "A trabajar, m'hijita" ("to work, my little daughter). A strange shock ran through my body as his hands touched me.
"How do I begin, Hermanito?" I asked as he took the egg and began rubbing it briskly over my head and shoulders. He tossed the egg at the bucket that stood near him. It splattered on the floor. Hermanito nodded towards Memo, Pachita's oldest son, who was sitting on the cot.
"The son of my flesh will give you instructions (Hermanito always spoke of Pachita in the third person calling her "mi carne" or "my flesh". )...
several weeks later:
She closed her eyes, placed her hands straight and stiff on her spread knees, and began taking deep breaths. The atmosphere in the room seemed to thicken as a powerful unseen presence descended upon Pachita. Suddenly her body quivered violently. Her right hand raised in a sharp straight-armed salute and a deeper, stronger voice than hers announced, "Estoy con ustedes, hermanos queridos" ("I am with you, beloved brothers"). Pachita had vacated the shell of her body to make way for Hermanito.
"Rita," Hermanito said, "I want you to sit very still now. Keep your eyes open and looking up at the ceiling. Do you understand me, little one?"
"Is it going to hurt me, Hermanito?" she asked, her voice quivering as she spoke.
"No, little one, you are even now being anesthetized," Hermanito said reassuringly as he stroked her hair. He took the new bottle of alcohol I was holding, opened it and poured it directly into her eye. I gasped, expecting the woman to cry out, but she just sat there. Then Hermanito sprinkled some of the balsam on the eye.
"Very well, little one, now hand me the cotton you have there." As I handed him the smaller cotton strips, he formed a square leaving the eye exposed in the center. He had stepped behind Rita and to her left. I moved directly in front of her, my knees brushing against hers. Then he asked Amado for the scissors and the old knife that lay on the altar. Amado quickly wiped each with a square of cotton soaked in balsam and handed the scissors to him. Hermanito took the scissors and raised them in a salute toward the altar as he began a prayer in Nahuatl, the ancient Aztec language. His first words were audible, then died down to a whisper. As he prayed, I saw that the area where we stood, and especially around Rita's head, became much brighter then the rest of the room, as though a soft spotlight were shining down on us. I could see clearly. I was to witness this phenomenon at each of the several hundred operations in which I assisted in the continuing months.
"Pray to God, little ones!" Hermanito pushed one point of the scissors into Rita's eye and began to cut. A pale reddish-white liquid trinkled into a piece of cotton that fell off her face and dropped onto her chest. I caught it and replaced it, my face only inches from her eye.
"Do you feel pain, little one?" he asked her. "No, Hermanito," Rita answered. Her head began to turn as she spoke. "Keep your eyes open--open." He took the knife from Amado, raised it in a salute, then began peeling a thin opaque scum off the center of the eye. It broke. He placed the first piece on the cotton I held out, then he gently lifted off the second part of the tissue and handed it to me. Again he poured alcohol into the eye, then placed a clean pad of cotton over it.
Even Mom and Dad had assisted in one of these. A boy, no older than sixteen or seventeen, was brought in by his family for an operation. He had been dumb from birth. The doctors had been unable to offer any reason for his condition. Hermanito explained to the family that a powerful curse had been placed on the child, while still in his mother's womb, by a jealous relative who could bear no children. Tonight the curse which bound the boy's throat would be unlocked.
He was instructed to sit in the chair facing the altar. "Come Don Alberto. You will assist me along with the dear doctor in this operation."
Daddy looked startled, but moved to Hermanito's side. Mother hovered in the background, clutching her purse to her chest. I knew she didn't want to be there. From the beginning she could sense the swirling presence of the spirits, and it frightened her. She had also voiced objections about the singing of hymns to Hermanito, and on several occasions when the name of God was invoked she said she had heard him mutter to himself, "soy yo, soy yo"- ("It is I, it is I")....
Hermanito slashed the boy's throat open, then took Daddy's hand and pushed it into the gaping hole.
"There, do you feel that lump in there, don Alberto?" Daddy nodded. "Good, good- now, when you feel it loosen, pull it out. Go on! Don't be afraid!"
Daddy pulled out a squirming bloody lump of matter, which was wrapped by the doctor in dark paper, bound with string and placed upon the altar. Then Hermanito's hand was back in the wound.
" I need a tiny key. Someone in this room has one!" No one moved. "Come now, dearest children. We can't stand here like this all night! It's in your purse," he added to no one in particular. "Oh! I have it!" Mama exclaimed excitedly. She pulled a bunch of keys from her purse; among them was a tiny brass key.
Hemrmanito took the key, pushed it into the hole and turned it.
After the boy was bandaged, Hermanito commanded him to speak. "Come on now, say after me; 'Pachita.'" After a long moment the boy, hesistantly, hoarsly, spoke his first word; "Pa-chi-ta." "Wonderfu! Now the docto's name- Dr. Carlos...That's it! Now say Don Roberto's name" ("Alberto" Daddy corrected) And even Daddy's eyes filled with tears as the boy joyfully sounded out his name. The curse had been unlocked.
The night of November 15, 1972 was damp and cold as I walked alone on the slippery path to Birdie's chalet. It had been drizzling earlier that evening but the clouds were lifting now and I could see a few stars peeping through. Well, maybe with luck it would snow before I left, I thought with a smile. Yesterday I had just about decided to take the next train out of Switzerland, but had changed my mind that morning. I couldn't go until I had some answers. So, perhaps, there would still be time to see snow after all.
I stopped. A dense black fog was forming all around me, blotting out the path. Within seconds I could see nothing. The dark mist was swirling, alive, filled with the presence of something more monstrous than anything I had ever before encountered. Voices began whispering, hissing incoherent words and laughter in my right ear. An ice cold breath touched the back of my neck under my hair.
"Hermanito, help me!" I gasped. The voices shrieked in hideous laughter. "We're going to kill you!"
I panicked and broke into a run. Something like a giant fist slammed into my back between my shoulders. I pitched forward in the thick darkness and instinctively reached out to break my fall. My fingers found the branch of a small bush and clung to it. I tried to scream out "Jesus!", but an iron hand closed upon my throat choking off the word. All I could do was scream in my mind, "Jesus, Jesus, help me!" "He can't help you!"
But then suddenly the grip around my throat loosened- the blackness lifted. I could again see the light of Birdie's chalet at the end of the path.
Birdie's eyes widened a little as I burst into the room. "What on earth is the matter with you!" she exclaimed. "I don't know, Birdie," I said, still shaking, "but I'm terrified."
Birdie hurried me into her little prayer room and closed the door. She took my hands in hers and began praying. I tried to focus on her words, but suddenly they sounded so far away. I felt dizzy. My eyes opened. The room seemed to have been taken up in a giant slow-motion whirlwind, spinning slowly round and around. The sound of voices began to build again. I turned my head towards the dark window on my left and froze. Outside I could see the faces of countless demons, contorted, twisted in indescribable rage.
"What is it Johanna?" Birdie's voice was muffled as though it were coming across a vast distance.
"Can't you see them Birdie, " I gasped, "Can't you see their faces?"
"No, I heard her voice say, "but I know One who can. Satan, in the Name of Jesus Christ of Nazareth, I command you to be gone! I forbid your presence here. I claim the protection of the blood of Jesus upon us. Go where Jesus sends you!"
Instantly the faces vanished. The room stopped spinning and was filled with a peace beyond all my understanding. They were gone.
I knew what had happened was a direct answer to my prayer. God had literally let me see the source behind my practices. Murderous demonic rage had been the spirits' reaction to my potential decision to accept Jesus Christ of Nazareth as He is, rather than as I had come to think He should be. The difference had been subtle, but vast nonetheless. There were still so many things I didn't understand, so many unanswered questions, but I knew beyond any doubt that I had been wrong about Jesus.