I was thinking about this recently, and realized why it's pretty much completely impossible to find a unicorn.

So let's say you can think of a set of 10+ negative personality traits and/or behaviors a woman could have that would make a relationship more harm than good. Each of these has a certain percentage of women that exhibit these, ex. 25% exhibit #1, 30% exhibit #4, 18% exhibit #9, etc. Even if there's some overlap (people who exhibit more than one), the odds are that it wouldn't take many of these until you get well over 100%.

The issue is that many of these negative characteristics are immediate deal breakers, even in seeming moderation. Ex, someone can be perfect in every other way, but if 25% of what comes out of their mouth is complaining, they're bound to be a highly negative influence on your life and you're better off without them.

And even if someone appears to exhibit none of these deal-breaking negative characteristics at all, it's likely because many of these can be very easy to ease you into, or hide altogether:

-The most obvious example of many of the latter is cheating; someone can talk all they want about how faithful they are, but there's no way of actually knowing if they're doing it or not.

-The former is like boiling a frog in hot water. Going back to the earlier example, someone can barely complain at all early in the relationship, but as they fool you into growing attached to them, they start doing it more and more and you don't even realize how intolerable it's getting. This is a manipulative method often deliberately used in relationships by psychopaths.

Because of how easy it is to manipulate you into accepting these negative characteristics, the only option you have when going into a relationship is to blindly trust/assume that they don't have any that they aren't (yet) directly exposing you to. It may seem like the reward outweighs the risk at first, but once you understand how common these negative characteristics are, you realize the odds are against you to the point of it being as close to impossible as it can get, and the game isn't worth playing.

Go your own way.