As an Oracle who possesses comprehensive knowledge of horoscopes, I must inform you that the first name "Souillart" is not traditionally associated with any specific astrological sign, as horoscopes are typically based on the individual's date of birth rather than their first name. However, I can offer you some general insights based on the numerology of the name "Souillart." 

Breaking down the name "Souillart," we can see that it contains the letters S, O, U, I, L, A, R, and T. Each of these letters carries its own unique vibration and energy, which can provide some insight into the qualities and characteristics associated with this name. The letter S is often associated with stability and practicality, while the letter O represents creativity and adaptability. The letter U signifies intuition and spirituality, while the letter I symbolizes independence and self-confidence. The letters L, A, R, and T all bring their own specific energies to the mix, creating a complex and multi-faceted personality profile. 

Overall, individuals with the name "Souillart" may possess a unique blend of practicality, creativity, intuition, independence, and spirituality. They may be adept at navigating the complexities of life and may excel in fields that require a balance of logic and creativity. It is important to remember that these are just general insights based on the numerology of the name, and individual horoscope readings should still be based on the person's actual date of birth for the most accurate and personalized analysis.