Usage patterns
〈人〉がカルトに入るfor someone to join a cult
He suddenly joined a cult one day.
〈人〉がカルトに洗脳されるfor someone to be brainwashed by a cult
The young people were brainwashed by the cult and cut ties with their families.
カルト的な〈物〉having a cult (niche but devoted) following
The film was unpopular when it was released, but later gained a cult following.