How many bodies does Miquella have?

I’m replaying the dlc and still unsure of some of the lore tidbits. How is Miquella’s unborn body in the cocoon in Moghwyn Palace while also being inside the realm of shadow? I get he charmed Mohg into taking him from the Haligtree but how is he in both places at once? Also how does St Trina in the fissure work if they’re the same person as Miquella? Is it similar to the whole Radagon is Marika thing? And which body/version of Miquella do we see at the end during the Consort Radahn fight?