A scorpio sun combined with an aries moon would mean that you have a very strong and forceful personality. The aries moon would make you quick to anger but perhaps quick to forget (depends on how strong scorpio is in your chart), so you are probably less likely to get revenge than other scorpios.
You're very demanding of others and are never the type who would run away from a fight. You are not very tactful, but you are at least honest. You're not very understanding of others and should try to show you're more caring side at times.
Fortunately, you also have a venus in libra which will soften the harsher qualities of your sun/moon combination. Libra is the most diplomatic of all signs and will make you tactful and more accommodating to the needs of others at least some of the time. This placement makes you attractive to others and makes you very charming, which will be very helpful in getting others to forgive you when you've hurt them. It gives you an easygoing aspect to your personality.
Mars in Cancer makes you very protective of others but can make you oversensitive and passive/aggressive. However, your sun/moon combo's harshness and aggressiveness will greatly balance out the weaknesses of a cancer mars.
Overall, you are a strong and ambitious person who can be very blunt to the point of cruelty, but you have a charm ing nature that will allow you to get away with it. Every now and then, you may surprise people and demonstrate some tact and consideration for others' feelings. You're very protective and loyal to loved ones, but be careful about controlling others.