Soo can anyone explain to me what is The Butterfly Maiden???

Pretty sure she can only fall in love or be loyal to one man.. which for her is the little master.

From what I've read, they are like tools that can only have one master and good pregnancy capabilities (can get pregnant multiple times and continue bloodline).

Oh my... Thank you for the explanations ><

how she has that power?? its from the first guy who give her that dream ?