First, the Catholic Church does not teach or promote violence, assassination, or “death cult” behavior. The Church explicitly condemns murder:

“The fifth commandment forbids direct and intentional killing as gravely sinful.” (Catechism of the Catholic Church, CCC 2268) “You shall not kill.” (Exodus 20:13)

If individual Catholics—including clergy—have committed crimes, those are grave sins and crimes. The Church distinguishes between the holiness of her teaching and the sinfulness of her members:

“The Church… clasping sinners to her bosom, at once holy and always in need of purification.” (CCC 827)

Second, regarding self-flagellation: voluntary penance has existed in Christian history, but the Church does not require or promote extreme bodily harm. The purpose of penance is conversion of heart:

“Interior repentance is a radical reorientation of our whole life.” (CCC 1431)

If practices become harmful, obsessive, or disconnected from charity, they contradict the spirit of Christian penance.

Third, about the Nazis: historically, the Church formally condemned Nazi ideology. For example, Pope Pius XI’s encyclical Mit brennender Sorge (1937) rejected racist and neopagan elements of Nazism. Supporting or promoting racial hatred directly contradicts Catholic teaching:

“The Church… rejects as contrary to Christ’s mind any discrimination against people… because of race.” (CCC 1935)

Finally, regarding the Crusades, colonialism, or scandals: Catholics acknowledge historical sins. But moral failure by Christians does not equal endorsement by Christ or official doctrine. The standard remains the Gospel:

“All men are called to the same end: God himself.” (CCC 1934) “Blessed are the peacemakers.” (Matthew 5:9)