Two-Souls are what Ramaus call true hermaphrodite individuals, 100% fertile and capable of self-impregnation. Two-Souls can be male-dominant, in which case they are basically a man with a pussy besides the normal male sex parts, or female dominant, in which case they are a woman with a dick and balls. Androgyny is not uncommon but most Two-Souls have a clearly defined dominant gender.
While Two-Souls can be born naturally although extremely rarely, thanks to information deciphered from ancient scrolls provided to the Lismorean Ramaus by the Kun Qalasi fennecs, it's now known that Two-Souls can be made. Although it's not known if the procedure works on non-ramaus.
Because this is considered sacred part of the Ramani culture, access to this information is restricted and requires special permission from the head librarian!
To perform the ritual, one requires a few arcane ingredients, arcane runes and casting circles, the proper incantations, all of which are described in the original and translated scrolls, and a ramau. It's not known if the procedure works on other species.
The ritual is brief, and can be performed in less than a couple of hours. If successful (there is a 1-in-20 failure rate), the ramau upon whom the ritual was performed will become a Two-Soul: A true hermaphrodite fertile across pretty much all species including themselves. The offspring of a Two-Soul self-impregnation tends to be an almost exact copy of the parent, except that it's not likely at all that the hermaphroditism will pass down to the offspring, those are born either male or female.
Two-Soul are absolutely fertile. It takes intense contraceptive methods to prevent one from impregnating or being impregnated.