To understand the Synodic Cycle of the Sun and the Superior Planets, an orbital diagram is helpful:
With direct and retrograde stations of Saturn, the distance between the Sun and stationary Saturn is rather consistent, between 108˚ to 109˚. Thus, a tridecile, or sesquiquintile aspect, forms with the Sun at the stations of Saturn. The relevance of the 10th harmonic aspect family (decile and tridecile) to the Saturn synodic cycle cannot be overstated.
Saturn is retrograde when sesquiquintile, trine, trioctile, biquintile, inconjunct, triseptile or opposite the Sun. These are all highly karmic natal phase angles. It has been my experience that a retrograde Saturn is much more powerful when also in close aspect to the Sun.
When the secondary progressed Sun and secondary progressed Saturn form subsequent aspects, if in close natal aspect, these periods mark the most karmic phases of an individual's life.
Here is an example of this phenomenon in the life of Dennis Wilson, the drummer for the Beach Boys:
Because the retrograde opposition of a superior planet to the Sun occurs when that planet is nearest to Earth (see point #6 in the above orbital diagram), its effect is most profound and can result in a karmic climax in the life of any individual.
In the life of Dennis Wilson, he was born with a highly karmic waxing triseptile of the Sun and retrograde Saturn, applying by only 28' of arc (Sun-Saturn arc is 153˚ 48' 50'').
I wrote in Volume V
"A profound karmic experience that Wilson had in October 1968 at his progressed Sun-Saturn opposition was of a highly fated nature. Driving on the Pacific Coast Highway in Malibu, he picked up two hitchhikers. Later that day, he picked up the same two girls a second time, and wound up taking them to his home. He left them there while he was at a recording session and when he came home in the middle of the night, he was met by a male stranger and a dozen others. It was Charles Manson.
It was reported that over the next year, until the abominable 1969 Tate/LaBianca murders, Wilson became friends with Manson, living in the same home. The horrid crime haunted him for the rest of his life, and was a contributing factor in a downward spiral of alcohol and cocaine addiction. He died in 1983 from an accidental drowning while drunk (with progressed Sun in 22˚ Capricorn 46' conjunct natal Venus, exact to 06')."