Did you know that a synastry chart only references a composite chart with planets of let's say another or his within your natal wheel and vice versa that join in a single map expression as the apex angle..Let's say you have your Venus in his 12th house in Leo over his Mars, and the composite or synastry chart has the chart portray a trine betw your Venus and his Mars trine in lets say Libra and Gemini consecutively..what do you think the blend would suggest. Remember nothing is ever to be forecast without the natal charts bearing out the energies with first consideration.
12th house Venus/Mars in Leo will have consideration with mention of children of course, secret worries anxieties of the Mars individual possibly thinking his love interest Venus experiences some misgivings with conception issues or that the love interest is shy and a very creative retiring type, which he takes the lead to draw out and the romance is experienced on a very loving clandestine level.
Now the composite chart has Venus in the 10th house with an opposition of Mars in it from the 4th house. You would not only have to know the natal charts of the individuals as to how the temperaments would be demonstrated bc of their individual charts, i.e.; His Mars in Gemini in the 5th, and his Mars trine to his Venus from the 9th in Libra..as well as these two planets in individual sectors within her chart for a blend. In the composite charts the influence of the individuals planets within each other's charts sectors..the blend of the planets in aspect with each other..etc..but the composite chart now combines these influences by augmenting all these planets places into one chart of their combined hour/ minute =planets/house/signs/aspects. Robert Hand has a book out with the many combinations that describes and gives examples how to understand these blends..it is good reading as are with all his books.
The composite would then read something like this..the opposite Venus Mars effect would strengthen the Venus character to emerge in the relationship and even disagree or discuss argumentatively about the way children should be reared within the house hold. The 4th house would bring into scrutiny the Father attitudes against the much too much Motherly prospective's? 10th vs 4th consideration's. But it is the natural trines/ease or squares/obstacles etc. other aspects which would bear out the individual house experiences not in the composite chart first, but in the individual charts, then the planets from their host positions rulings arriving into other individuals houses to be considered of fated testimony.. The composite is a guide post to activities that are of mental integration efforts that each chart promises on a very personal experience. The opposition of Mars and Venus in the composite would be defused by the trine energies each experienced with each other's planets falling within specific house areas each owned. It is a very complicated process
which is not an easy task to transmute or interpret. It takes a knowledge of the individual and how they integrate energies from their own charts into everyday experiences. And then there are the transiting energies of each passing day or night movements.
It is enough to say that it takes a long while to chart just how these influences will draw the unions to actualize activities into events
Take care that your potentials will be realized gainfully
All the best
Vyri