TheRedPill Dictionary

unicorn

A unicorn is an idealized fantasy girl. It's a girl who reflects your own weaknesses and beta desires.

So you have a noble quest to find a loyal, pure maiden who isn't hypergamous, slutty (at least not for others, but for you it's okay), or dishonest. These girls don't exist. But many guys want them so they can feel fulfilled as men and gain purpose in their lonely lives.