Is there something that is hard or impossible to handle with this aspect?
The Sun / Pluto square indicates regeneration in some part. Whatever Pluto touches, it has to undergo a change in its essential structure in order to become more highly developed. The square makes inner drive very difficult. Transformations do occur but not without tensions and breakdowns. This presents a real challenge when striving for evolutionary achievement. If you take Pluto by itself, the squares indicate that individuals often attempt the impossible. There can be problems with impatience and overbearing dictatorial attitudes that only serve to defeat their purpose. These attitudes will affect the houses that carry the 2 planets making the square, the signs and houses they rule, and the signs and houses where their exalted rules ar found. In a nutshell, a conscious effort of the will is required to change these behavorial pattern and give the person a new start. The power of the will must be exerted so that the person can consciously choose their focus of attention, selecting the thoughts to be entertained by their conscious mind. Pluto rules Scorpio, which rules the emotinos that are sometimes too deep for tears, demands that the desires represented by Mars (co-ruler) be lifted up to a higher expression and rise from the lower nature. Anyone can be disagreeable, can hate and resent, but to love, to understand, and to raise the status of the consciousness takes a definite conscious exercise of the power of the will which Pluto deals with in a chart. Since Pluto rules recycling, the person must clean up and recycle the residues of their physical, emotional, and mental bodies as well as of their environment. The left-overs of old conditions must not be allowed to poison the ongoing process of life.