ANY mars as synastry does not work off signs but MATHS
There is little point in looking for astrological sun *signs* in synastry as there are too many permutations. In a male chart you would look at moon & venus, any planets in 7th house, then sign/planet that rules that house. In a female chart you would look at sun & mars, then any planets in 7th house and then sign/planet that rules this house. You would NOT look for the SIGN that rules your 7th house, only the traits of that sign. Also for 2nd marriage/partner you look to 9th house,3rd marriage/partner would be 11th house and 4th partner 1st house.
Please understand synastry (comparing two charts) does NOT work off SIGNS but mathematical aspects one chart makes to another. For example and opposition is 180’ a square 90’ sextile 60’ and trine 120’ its pure maths. What attracts you to another person is their ASCENDANT sign not Sun sign. This is the chemistry, lust and attraction factor. If you get your chart and find your Asc sign from astro.com then anyone’s sun sign that falls conjunct your Asc or in your first house is excellent as there would be so much in common. Also excellent if someone's sun conjuncts your Descendant/marriage house. The angles are very sensitive in synastry. Astro is *THE* only site where you can even get these synastry bi wheels FREE of the net!!
Ask Kevin: Karmic Aspects in Synastry
How to approach Synastry