Complex sentence: Flowers joined the Church of Satan in 1972 and later became involved with the "Order of the Trapezoid" which served as segue into his current membership in the Temple of Set, of which he holds the degree of "Magus V °".
Split into simpler sentences: Flowers joined the Church of Satan in 1972 and later became involved with the "Order of the Trapezoid". This organization served as a segue into his involvement with the Temple of Set, an organization which he currently holds the degree of "Magus V °".