Oksana - a Rusalka from the birch grove

This being lives in or near a birch grove downstream from the watermill where Ivan along with three companions retreated after Irina's. The rusalka is apparently aware of the mystical power of the birch sap. Upon meeting Lada in the grove, asked her many questions about her companions, and then, seemingly, traded some sap for the lives of Ivan and Prokhor (though this could be Lada's interpretation). The rusalka appeared to the two of them in the stream flowing by the mill while Lada was gone, and seems to have enchanted Prokhor. The rusalka revealed nothing about a possible relationship with the forest tsar - she insisted she acts independently. She did hint at having had an affair with Dmytro Mstislavovich - a prince who subsequently abandoned her.