Helloooo Doublefish,
How's it going with this guy? The synastry looks pretty good. There are couple of concerns but then, there usually are!
OK let's take it from the top.
The kind of partner (or traits of) a woman is looking for is her Sunsign, Mars sign, 7th cusp and cusp ruler's sign(s). For you that's Pisces Capricorn and Aquarius.
The kind of partner (or traits of) a man is looking for is his Moonsign, Venus sign, 7th cusp and cusp ruler's signs. For him that's Scorpio, Capricorn, Leo and Sagittarius. Virgo is intercepted in his 7th house so he would find them appealing too.
You have plenty of Capricorn to offer him, and Leo Rising! He has Aqua Rising, and a stellium in Capricorn to match part of your needs. So the opposites attract phenomenon is happening with the complementary AC/DC axes -nice!
The 4th, 5th, and 7th houses are most important to synastry because they rule home/deep roots, romance, and relationships.
His Scorpio planets are in your 4th. Mars could add conflict here, but Moon is powerful here. There's possibly something comfortable or familiar about him. His Sun and Mercury are in your 5th -you see him as a romantic partner. No planets are in your 7th or conjunct your Descendant so he doesn't necessarily look like long-term relationship material, but the 4th house activation might be enough to change that.
Your Jupiter is in his 5th -so he may see you romantically. No planets in his 4th or 7th so he may not view this as long-term. If you want to know what the specific planets mean in houses, go to the skyviewzone website.
Now you two have a ton of conjunctions -unification of your energies. Part of this is being born at roughly the same time so outer planets are in the same places. Here's some that stand out:
There's a nice Moon conjunct Venus but these are Yin energies. Could be a lovely emotional rapport effect here though.
Pluto conjunct Mars -very powerful contact at close orb, healing or destructive passion
Pluto conjunct Moon -emotional intensity
Mars conjunct Venus -Cupid score's a bullseye w/ a perfect Yin-Yang match! Congrats!

Venus conjunct Venus - very nice Yin energies again with matching love natures, common tastes, etc.
Neptune conjunct Venus -profound spiritual love connection
Saturn conjunct Venus -another powerful, heavy connection that can go either way -marriage and commitment, or a block and fears of it. This and/or the Saturn Moon dynamic could relate to your reluctance (or irrational fear) to trust.
Lunar Nodal axes are closely conjunct in the same direction and his AC/DC is conjunct your nodes -these are karmic, past-life soulmate indicators. [We have many soulmates of different types and this is not fairytale romance. There may be a karmic debt here!]
There's a healthy amount of nasty squares too but no 'dealbreakers'. This is good because couples need challenges and differences or the relationship stagnates. The only one that's a significant problem IMO is that your Suns are tightly square which is a clash of egos. There's a decent amount of trines and sextiles to support you too, though.
It looks
very good so go for it! Your only real challenge might be getting a Sagittarius Sun and Merc to commit. His Venus in Cap helps in that regard, but give this guy space, freedom, and be patient.