The original Christians of the New Testament (Jesus Christ, Blessed Mother Mary, 12 Apostles sans Judas Iscariot, St. Paul, the other Jewish disciples, who were all anti-Judaic).
The saint should have converted them to mulch. You can't change their true nature. This is why Christianity suffers. They let the Jew run rampant with a Christian disguise.
The original Christians of the New Testament (Jesus Christ, Blessed Mother Mary, 12 Apostles sans Judas Iscariot, St. Paul, the other Jewish disciples, who were all anti-Judaic).
Nicholas Donin:
https://en.wikipedia.org/wiki/Nicholas_Donin
Pablo Christiani:
https://en.wikipedia.org/wiki/Pablo_Christiani
Johannes Pfefferkorn:
https://en.wikipedia.org/wiki/Johannes_Pfefferkorn
Benjamin H. Freedman:
https://en.wikipedia.org/wiki/Benjamin_H._Freedman
Bobby Fischer:
https://en.wikipedia.org/wiki/Bobby_Fischer
These were Jewish converts to Catholicism who made it a big part of their life's work to expose the evils of Jewry.
To your point, these types are exceedingly rare, but authentic conversion does happen.