Odysseys during his travel to the Underworld in Book XI of the Odyssey meets the "phantom" of the deified Heracles:
And after him I marked the mighty Heracles—his phantom; for he himself among the immortal gods takes his joy in the feast, and has to wife Hebe, of the fair ankles, daughter of great Zeus and of Here, of the golden sandals.
Why are there two versions of Heracles in the afterlife? How is the phantom version Odysseys meets different from the one enjoying himself in Olympus?