The four transformers of Zi Wei Dou Shu, namely Lu, Quan, Ke and Ji (祿權科忌) are the pivotal reference points of fate in the different periods of the charts. The reason why I refer to them as “transformers” is largely a question of terminology. We see the trajectories of the transformers as indicators of events, and these paths may lead us to useful clues. I guess most practitioners by now have some ideas that Lu denotes the beginning, or cause, and Ji denotes the end, or the effects. Cause and effects are the constant in the rational universe and I do not have to explain further. Also most people would have understood Quan as the medium, or the processes and Ke as the influence.
In the San Cai relationships of transformers, Lu, Quan and Ji are bound together in the respective order of Heaven Earth and Man. Ke is out of this equation and largely remain an outside influence. In the interplay of transformers, we fly Lu and Ji to take note of the cause and effects of a feature (e.g. Wealth). When Hua Lu and Hua Ji are not obvious we focus on Hua Quan. While conventional ZWDS practitioners regard it as process, the medium is a lot more complex. The medium hides “reason”. My personal opinion thus differs. Also conventional ZWDS practitioners think that Hua Ke is weak. It certainly denotes “help” to lessen misfortune and increase fortune, but cannot be used to change outcome. My personal opinion also differs here as it has the potential to be a major succour.
Chinese destiny reading is usually not a one way street. If potential problems are identified, there is usually a remedy (or cure) that can be used accordingly. This concept is known as Yong Shen (用神; useful god, or divine usage). The fundamental basis of finding Yong Shen is firstly based on the holistic template, and identification of faulty components, to improve upon. In Bazi, the Yong Shen is derived through exhaustive mean of elemental interplay, assessment of strengths/weaknesses and balancing.
In Zi Wei Dou Shu, it is much easier, as the pattern is laid out quite clearly and cures/remedies can be inferred by certain logic from observing the transformers trajectories, palaces, stars and period. And you can look for Yong Shen for every palaces you seek to enquire. Some examples: Look for benefactors by following Hua Ke in respective palace. Seek wealth luck from direction of where palaces send Hua Lu to wealth palace. Reduce self Hua Ji in birth date selection by elimination down to hours (Wen Chang/Wen Qu). Putting some item in house to curb continuous career problem (culprit is again self Hua Ji). Some are obvious and some are closely guarded information/trade secrets. There are many remedies for many situations. But knowing how to find them is another question altogether.