Some astrologers consider the 'chart ruler' or 'dispositor' to be the overriding influence of a chart. And sometimes....often this is true.
Your authenticity always comes from your Sun.
But the Sun is not always the most powerful influence in the chart -it would be so much easier on everyone if it were.
To find a 'dispositor' find the ruler of each planet in the sign it's in.
For instance, if you have Sun in Gemini, Moon in Virgo, Mercury in Gemini, Venus in Cancer, Jupiter in Taurus, Sagi ascendant.....example.....
Sun is disposited by Mercury
Moon is disposited by Mercury
Venus is disposited by Moon
Jupiter is disposited by Venus
Ascendant is disposited by Jupiter
etc...till you have all the dispositors.
Usually the ruling planet is the one which disposits the greatest number of placements.
HOWEVER: because this is a 'case by case' issue, you cannot always go by this method.
If the Moon is on the MC, usually IT will rule the chart.
Any planet within 4 degrees of the MC is usually the chart ruler.
Sometimes the ruler of the ascendant is the chart ruler (if there is no clear dispositor.)
However, usually there will be a tendency toward a chart ruler.
Except for the Sun, a planet in a cadent house will usually not be the chart ruler, unless it is the clear dispositor....
LOL....confused yet?
This is why the rules of this type are known but not totally explainable.
We have to see a chart, and then it is much easier.
Arijana, now that Isee your chart I see a very powerful Pluto, very near the ascendant, and tend to see that as the most powerful planet in your chart. However, it trines, very closely, your Sun also in an angular house, though not close to the angle. These planets are powerful together and will serve you well, and it probably would be good to always think of them together.
LIN