There's tonnes of ways to narrow down the type of succubus. Where's your attention to detail?
-Language. Do they speak? If so, do they use modern English, Olde English, another language, or an alien tongue? Are they described as having an accent?
-If they /don't/ speak, do they use telepathy? Sentences, single words, or thoughts? Is it two-way?
-You say they can read minds - any clue on whether that's sentences or just impressions? Can they locate you by your thoughts? Can they /affect/ your thoughts?
-Size of wings. Massive bat-like things or tiny little leather-fairy jobs? Either way, are they able to fly, or are they just for display?
-General appearance. Are there any constants in their descriptions? Are they human-with-wings-and-tail, the above but in a different colour (blue, red, green), the above but with minor demonic attributes (fangs, pointy ears), or full-on demons?
-Magic? Illusion, mind control, magic ropes to ensnare you with.
-Do they have a hierarchy? How rigid is it?
-Are there incubi as well, or just succubi? If both, how do they relate to one another?
-Any information about where they come from? Are they a natural surface species? Escaping from a hellgate? Summoned deliberately? Summoned accidentally?
-Do they kill, or just drain energy? If they kill, how? By massive energy drain, vampiric bloodsucking, general mutilation?
Details, Storme Hawk! You have two sources for these creatures - unless they're incredibly background (in which case they'll probably just pop out of existence), you should be able to write a thesis on their biology.
(All right, I'm being deliberately facetious with the tone of this; I'm going for 'irritable professor', which isn't really Me. So don't take the framing comments too seriously. What I am serious about is that, with enough information, you can probably pin them to a precise world. Want me to take a look and write the thesis for you?)
hS