Quoting Lawrence J. Epstein’s Converts to Judaism: Stories from Biblical Times to Today, pages 2–3:
There are […] a lot of unusual conversion stories. One of the strangest involves Reuel Abraham. His birth name was Karl Heinz Schneider. He spent his teen years organizing [Fascist] youth battalions. At age eighteen, he volunteered for combat service in the Luftwaffe. Dive-bombing was his unit’s specialty.
One day, Schneider was in [Fascist]-occupied Poland, walking through a town. There he witnessed some storm troopers murdering Jews in a synagogue’s courtyard. Schneider particularly noticed that the rabbi died clutching the Torah.
The incident changed Schneider’s life. He started to disobey orders. He dropped bombs on uninhabited areas. He adjusted detonators so that his bombs wouldn’t explode. When World War II ended, Schneider vowed to do penance for twenty years.
He went to work in coal mines, anonymously donating two-thirds of his salary to organizations aiding war orphans and survivors of the concentration camps. He taught himself Hebrew, and, taking a new name, he began to attend synagogue services.
After the twenty years, Schneider sold his farm and moved to [occupied Palestine]. He approached religious authorities about becoming a Jew. The authorities, at first not believing his story, investigated.
When they realized he was telling the truth, they considered his past and what he had done since and accepted his application. Taking the name Reuel Abraham, he became both a Jew and a citizen of [occupied Palestine].
That last bit should be particularly alarming: here is someone who thought that he could atone for his associations with the Axis by trading one ethnostate for another. This is a common theme for the Axis employés or their descendants who settled in occupied Palestine: settling there is supposed to be a ‘happy ending’ for them, though many have insisted that their attraction to Judaism was sincere. Take, for byspel, Rabbi Berel Wein:
“I was born and brought up in Germany. My father was an officer in the élite SS killing squad, the Totenkopf (Deathhead Squad). He served throughout the war and after it was over successfully eluded apprehension. But his crimes were so heinous that years later the West German Republic continued to pursue him. Finally, he was caught and imprisoned for ten years. Later, because he was so old, they reduced his sentence and let him out after four and a half years.
[…]
“I loved Israel so much I just stayed on and applied for citizenship. Also, after about two years of learning about Judaism I decided to study to become a Jew. A few years later I earned my Ph.D. in microbiology and became a Jew. I married and settled in Jerusalem. My wife was a German Lutheran, but she, too, converted. A psychologist might interpret my conversion as sublimating my guilty feelings, but I prefer to think about it as fulfilling my Jewish destiny. Don’t ask me how or why, but here we are — an observant Jewish family. And we are very happy living as Jews.[”]
I dug further and discovered that a man with a family connection to Hitler does indeed live in Israel as an Orthodox Jew. Virtually unnoticed in the English-speaking world, he was exposed seven years ago in an Israeli tabloid. Then he sank from sight. I went to Israel to meet him — and on the way I was plunged into the strange subculture of the Nazi-descended Jews.
I am walking through the alleys of the Old City of Jerusalem, to meet Aharon Shear-Yashuv. He is the son of a [Fascist]. And yet he was a senior rabbi in the Israeli armed forces.
He lives in an apartment in the Jewish quarter, near the Western Wall. I walk through a pale gold alley; Orthodox Jewish men in long black coats and round fur hats dart past. He opens the door and looks like every other rabbi I have ever met — a black suit, a beard, a questioning shrug. He takes me into his study, settles into a chair, and says, in a thick German accent: “My father was in the Waffen-SS.”
He was, he explains, born in the Ruhr Valley in 1940. During the war, his father served on the eastern front with Hitler’s élite troops. What did his father do in the Waffen-SS? “I don’t know,” he says calmly. “When I grew up I tried to ask, but there weren’t really answers.”
[…]
Today, he believes [that] Germany is doomed. “People there don’t get married, and if they do they have one child,” he says. “But the Turks and the other foreigners have many children. So it is a question of time that Germany will no longer be German.” Why does he think this has happened? “I think it is a punishment for the Holocaust,” he says, matter-of-factly. “Germany will leave the stage of history, no doubt about it.”
[…]
Later that day, I meet the man who brought me here to Israel, the man who started all this — the so-called Jewish Hitler. […] He is holding two pieces of paper. One is a family tree; the other is a printout of an account of the life of Alois Hitler Junior — Adolf Hitler’s half-brother. […] He begins to tell me what happened to his mother during the war. She worked as a typist for the Wehrmacht in Poland and she saw dead Jews hanging in the town squares.
[…]
And then, to my surprise, he calls his son — his Israeli son — a fascist. “When I hear my own son speak — as I did last weekend — I sat like this,” and he does the Hitler salute. “Two of my sons are chauvinists and one of them is even partially racist. I can’t listen to fascistic discourse. I don’t suffer that.” They talk about the Palestinians with contempt.
Similarly, there is the tale of an HJ member who grew up to become a ger:
Before meeting Patricia, Theo didn’t have any Jewish friends and with disarming honesty admits that he probably wouldn’t have wanted any.
“I grew up in an anti-Semitic surrounding, I probably myself had anti-Semitic views but it never ever came to the discussion,” he acknowledges. “So I had nothing to do with Jews.”
All that changed when he was invited to travel to Israel with his wife and a group of Jewish friends.
On their first night in Jerusalem Theo was having trouble sleeping and walked over the window of his hotel room to look out through the curtain.
“It was almost as if I was struck by lightning,” he recalls.
Below him was Jerusalem’s holiest place for Jews, the Western wall. The golden Dome towering above it and glistening in the night sky.
He watched as the sun rose over the dome, sitting there transfixed for six or seven hours as the beautiful stories of the Old Testament he had heard as a young Catholic altar boy in Munich flooded back to him.
The emotional effect was profound and when he returned to the UK he knew exactly what he needed to do.
When Theo approached his local rabbi to tell him he wanted to convert, the holy man simply said: “What took you so long?”
The conversion process took four years, throughout which Theo had to learn Hebrew and study the Torah in depth.
There was also one Axis sympathizer, a former Klan leader, who adopted Judaism, though he differed most significantly from these other examples in that he never settled anywhere in West Asia. (A wise decision on his part.)
Converts to Judaism: Stories from Biblical Times to Today, pages 148–150:
Consider, for example, the strange case of Larry Trapp, at one time the grand dragon of the Nebraska Ku Klux Klan. In June 1991, Trapp, acting on his Klan beliefs, called Michael Weisser, who was a cantor at a Reform congregation in Lincoln. It was an unpleasant, threatening call.
Cantor Weisser phoned the police, who installed a tap on the phone. Only a few days later, Weisser got a package filled with hate literature from the Klan, the [German Fascists], and the Aryan Nations. Weisser immediately thought of Larry Trapp, who was infamous in the area for sending such materials. Although only in his forties, Trapp was blind and, because of his diabetes, confined to a wheelchair.
Weisser discussed the situation with his wife, who made a startling suggestion. She thought that her husband should speak with Trapp, not in a hostile, confrontational way but in a kinder manner. Weisser got Trapp’s number. The phone’s answering message was filled with vile hate against blacks and Jews. Undaunted, Weisser left a message telling Trapp that one day he would have to answer to G-d, and so he should think about what he was doing.
Weisser made a follow-up call to Trapp in a few weeks, reminding him that the [German Fascists] hated people with physical handicaps. Weisser would not quit. He kept making the calls.
Trapp finally did pick up the phone, saying Weisser was harassing him and threatening to have the cantor arrested.
Weisser shocked Trapp with the response, saying he thought Trapp might need a lift to the grocery store.
The article in the paper came two weeks later. Larry Trapp had been sponsoring an anti-Semitic cable television show, but now he pulled it off the air. The article suggested Trapp was rethinking his racist views.
Weisser immediately called, wanting to find out whether the article was accurate. Trapp did not want to talk about it then. But the time came. Trapp called the cantor and said it was time to get away from what he had been doing. He asked for help.
Weisser and his wife visited Trapp. The cantor shook his hand. Trapp cried. He took off two rings that had swastikas, asking Weisser to get rid of them. They spoke for several hours. The Weissers left, and with them they took cartons of [Fascist] flags, hate-filled literature, and, tellingly, Trapp’s Ku Klux Klan robes. Larry Trapp was cleaning his life.
Trapp apologized for all he had done. In early 1992, Trapp announced that he was studying Judaism. Eventually his illness made him unable to take care of himself. The Weissers invited him to move in with them, where Mrs. Weisser took care of him after giving up her job. Trapp completed his conversion to Judaism in June 1992. He died at age forty-three the following September. Larry Trapp, former Klan leader, former [Axis] sympathizer, was buried in a Jewish cemetery.
Uriel Heilman wrote in 2015 that at least ‘400 descendants of Nazis have converted to Judaism and moved to Israel, according to filmmakers who made a documentary about the phenomenon several years ago’, presumably referring to the 2011 documentary Hitler’s Children, though I am unsure if anybody has verified this estimate.
Lastly, while not necessarily related to any Axis staff, there is a comparable parallel with Afrikaners settling in occupied Palestine:
Among the first Afrikaner converts to make aliyah were the Taljaards from Randfontein, a gold-mining city near Johannesburg. They came in the mid-1990s and began raising sheep in the settlement of Susya, where they were often involved in violent clashes with Palestinians from nearby villages in the South Hebron Hills. Jacob, the eldest of 14 children in the family, was killed in a tractor accident several years ago. He once famously told an Israeli television reporter that he “loved” the apartheid system and thought it was “the best thing in the world.”
I once read a rumour about an Afrikaner converting to Judaism in the 1990s and settling in the occupation because he couldn’t get enough of apartheid. It sounds like a joke, but I would not dismiss it out of hand either.