The relative strength of this aspect depends on how exact it is; that is given by the "strength" and "orb" in the header above this reading in your own personalized book You and the Universe. Depending on its strength, this could be the most significant aspect in your chart! You were born as the Sun left the sky to descend beneath the Earth where it can no longer be seen. Sunset is a point of balance and transition: of day into night, of light into shadow, between the outer and the inner, and in astrology, between the self and the not-self, the intimate other. The Sun opposed the Ascendant is the same as the Sun conjunct the Descendant or the seventh house cusp, and this is how this aspect will be interpreted. The Descendant intensely symbolizes what we don't identify with in ourselves, and therefore project onto or seek in others or through intimate relationships. With the Sun here you need partners or intimate one-to-one relationships to find your center, sense of purpose, and to fulfill your goals. If you're a man who judges himself, you may experience this part of your nature as disintegrative and demoralizing. But whichever sex you are you need others through which you - and so that you - can shine! This may be difficult to accept, but there is nothing wrong with this need or dependence. It just is. It is WHO YOU ARE!
Souls who have incarnated at sunset, as you have, often find or model their own will and sense of purpose on that of their partner. In your intimate one-to-one relationships your partner will be dominant and hold the power. This may occur through your helping them to shine or through your learning to adjust to their needs and their demands and by putting yourself second. You tend to find your sense of self as part of a couple rather than as a separate ego.

IF the Sun is in your sixth house AND within 3° - 4° of your Descendant (check the orb in the header), THEN its expression through your seventh house is at least as strong as through your sixth; if its orb is less than 1.5°, it should be read as though it were in the seventh house and not in the sixth at all!