The aspects of Mars with Saturn.
These celestial bodies were called malefic in antiquity because they cause impediments, on the other hand the benefits they provide are usually achieved with effort and struggle or with arduous work.
Mars is represented as a circle with a cross on top, it is the image of dense matter above what is more subtle, Mars represents raw energy, this energy is necessary for life, perhaps both Saturn and Mars have in common that they represent the most ancestral and primitive part.
Saturn is the structure, if you seek emotion the body we would point to the skeleton, however to transcend our nature we do not use its energy, although without the support it gives us we could not endure and would become a shapeless mass. Therefore Saturn and Mars despite being considered malefic, are necessary and provide a benefit.
When Mars Saturn are united by an aspect, the individual has a vivid awareness of their limits, however when the aspect is tense, it can happen that they try to overlook those limits, a square of Saturn with Mars can give a character very resistant to suffering and pain. Saturn sets limits and Mars pushes forward, when we have repeatedly lived within a limitation, we also become more resistant, so that those who have never had to suffer those limits will succumb sooner to similar trials.
Therefore Saturn in aspect with Mars hardens, on the other hand it is also an excellent aspect for physical discipline, an athlete or really any individual dedicated to a long-term task will be favored by the aspects of these planets, the good aspects of Mars with Saturn favor effort and achievement, however results may not be immediate, and it will be necessary to find other additional data in a natal chart to clarify a final result.
The aspects of opposition cause, when both planets are strengthened, very marked moments of dynamism that later become periods of stagnation, if other aspects do not intervene, the individual can pass through very marked periods of euphoria and stillness.