Hier ist ein gutes Beispiel dafür, wie stark sich bestimmte mythische Themen in unterschiedlichen Versionen voneinander unterscheiden können.
Aus Homers "Odyssee" wissen wir ja, daß Achilles sich nach seinem Tode im Hades befindet und dort von Odysseus besucht wird.
In der folgenden Version verhält es sich aber ganz anders:

1. Philostratos: Heroicus

[...]
The shrine faces Lake Maeotis (which is as large as the Black Sea and empties into it), and contains statues of Achilles and Helen, who were joined by the Fates: love comes from the eyes, and the poets sing of love from this source; but Achilles and Helen never had been seen by each other (she being in Egypt (1) and he at Troy), and began to love each other after discovering the source of physical desire in their hearing.

Yet for their immortal life together no land beneath the sun had been destined, and the Echinades islands opposite Oeniadae and Acarnania had already been polluted when Alcmaeon, after killing his mother, settled on the silt deposits of the River Achelous, territory that had not yet existed at the time of his crime.

Thetis asked Poseidon to create a new island from the sea in which they could settle; he remembered how long the Black Sea was, and that sailing it offered no lodging because there was no island in it; and so brought forth the island of Leuke [Λευκή], whose size I have described, as a home for Achilles and Helen and as a stopping point and anchorage in the sea for sailors. Poseidon controls all liquid substance everywhere, so he noticed that the rivers Thermodon, Borysthenes, and Danube empty with irresistible and ever-flowing streams into the Black Sea, and headed up the silt which they sweep from their Scythian headlands into the sea and fashioned an island of the size I have described, and fastened it to the floor of the Black Sea.

There Achilles and Helen first saw and embraced each other. Their wedding was celebrated by Poseidon himself and Amphitrite, and all the Nereids and rivers and their divinities that flow into the Lake Maeotis and the Black Sea.
It is said that the island is inhabited by white birds, which are wet and smell of the salt air. Achilles has made them his servants, and they clean his grove with all the breeze from their wings and the moisture from them, which they do by flying low and a little raised off the ground.

The island may be visited by men who sail this vast sea, and stands as a hospitable haven for their ships; but neither sailors nor dwellers in the region, Greek or barbarian, may ever make it their home. If they anchor and sacrifice there, they must board their ships at sunset and not spend the night on land; if the wind is favourable they sail away, otherwise they tie up and sleep below deck. For it is then that Achilles and Helen drink together, engage in song, and sing their love for each other, Homer’s verses about Troy, and Homer himself.
[...]

[54, 3-12]

(1) Nach der Eidolon-Version des Mythos ist die echte Helena in Ägypten geblieben und nur ihr Abbild nach Troja gereist.

Und diese Version berichtet nicht nur Philostratos.