Complex sentence: The Ku Klux Klan robes are based on the Capirote that are worn by the Nazarenos (Brotherhood of San Esteban) (see Holy_Week_in_Seville), ironically the capirote has its origins in Catholicism, while the Ku Klux Klan is an anti-catholic White Nationaist religious organisation.
Split into simpler sentences: The Ku Klux Klan robes are based on the Capirote that are worn by the Nazarenos (Brotherhood of San Esteban) (see Holy_Week_in_Seville). Ironically the capirote has its origins in Catholicism, while the Ku Klux Klan is an anti-catholic White Nationalist religious organisation.